scpi_usbtmc_libusb.c: Consistently check for < 0 (libusb calls).

diff --git a/hardware/common/scpi_usbtmc_libusb.c b/hardware/common/scpi_usbtmc_libusb.c
index 9d96bcca7f2220aedfff5533e586833abfa37524..c38845439fd04c901a32a482010622490a1a2f91 100644 (file)
--- a/hardware/common/scpi_usbtmc_libusb.c
+++ b/hardware/common/scpi_usbtmc_libusb.c
@@ -109,14 +109,14 @@ static GSList *scpi_usbtmc_libusb_scan(struct drv_context *drvc)
                return NULL;
        }
        for (i = 0; devlist[i]; i++) {
-               if ((ret = libusb_get_device_descriptor(devlist[i], &des))) {
+               if ((ret = libusb_get_device_descriptor(devlist[i], &des)) < 0) {
                        sr_err("Failed to get device descriptor: %s.",
                               libusb_error_name(ret));
                        continue;
                }
 
                for (confidx = 0; confidx < des.bNumConfigurations; confidx++) {
-                       if (libusb_get_config_descriptor(devlist[i], confidx, &confdes) != 0) {
+                       if (libusb_get_config_descriptor(devlist[i], confidx, &confdes) < 0) {
                                sr_err("Failed to get configuration descriptor: %s.",
                                       libusb_error_name(ret));
                                break;
@@ -193,14 +193,14 @@ static int scpi_usbtmc_libusb_open(void *priv)
                return SR_ERR;
 
        dev = libusb_get_device(usb->devhdl);
-       if ((ret = libusb_get_device_descriptor(dev, &des))) {
+       if ((ret = libusb_get_device_descriptor(dev, &des)) < 0) {
                sr_err("Failed to get device descriptor: %s.",
                       libusb_error_name(ret));
                return SR_ERR;
        }
 
        for (confidx = 0; confidx < des.bNumConfigurations; confidx++) {
-               if (libusb_get_config_descriptor(dev, confidx, &confdes) != 0) {
+               if (libusb_get_config_descriptor(dev, confidx, &confdes) < 0) {
                        sr_err("Failed to get configuration descriptor: %s.",
                               libusb_error_name(ret));
                        continue;
@@ -255,13 +255,13 @@ static int scpi_usbtmc_libusb_open(void *priv)
                uscpi->detached_kernel_driver = 1;
        }
 
-       if ((ret = libusb_set_configuration(usb->devhdl, config))) {
+       if ((ret = libusb_set_configuration(usb->devhdl, config)) < 0) {
                sr_err("Failed to set configuration: %s.",
                       libusb_error_name(ret));
                return SR_ERR;
        }
 
-       if ((ret = libusb_claim_interface(usb->devhdl, uscpi->interface))) {
+       if ((ret = libusb_claim_interface(usb->devhdl, uscpi->interface)) < 0) {
                sr_err("Failed to claim interface: %s.",
                       libusb_error_name(ret));
                return SR_ERR;
@@ -385,7 +385,7 @@ static int scpi_usbtmc_bulkout(struct scpi_usbtmc_libusb *uscpi,
        ret = libusb_bulk_transfer(usb->devhdl, uscpi->bulk_out_ep,
                                   uscpi->buffer, padded_size, &transferred,
                                   TRANSFER_TIMEOUT);
-       if (ret) {
+       if (ret < 0) {
                sr_err("USBTMC bulk out transfer error: %s.",
                       libusb_error_name(ret));
                return SR_ERR;
@@ -409,7 +409,7 @@ static int scpi_usbtmc_bulkin_start(struct scpi_usbtmc_libusb *uscpi,
 
        ret = libusb_bulk_transfer(usb->devhdl, uscpi->bulk_in_ep, data, size,
                                   &transferred, TRANSFER_TIMEOUT);
-       if (ret) {
+       if (ret < 0) {
                sr_err("USBTMC bulk in transfer error: %s.",
                       libusb_error_name(ret));
                return SR_ERR;
@@ -437,7 +437,7 @@ static int scpi_usbtmc_bulkin_continue(struct scpi_usbtmc_libusb *uscpi,
 
        ret = libusb_bulk_transfer(usb->devhdl, uscpi->bulk_in_ep, data, size,
                                   &transferred, TRANSFER_TIMEOUT);
-       if (ret) {
+       if (ret < 0) {
                sr_err("USBTMC bulk in transfer error: %s.",
                       libusb_error_name(ret));
                return SR_ERR;