rigol-ds: fix search for the closest vdiv.

We try to find the smallest diff by comparing each diff with
the previously known smallest diff, so initially, this smallest diff
should be INFINITY so that we are sure to find a smaller one.

This fixes the following exception:
sr: rigol-ds: Negative vdiv index: -1.
Caught exception: not applicable

diff --git a/src/hardware/rigol-ds/api.c b/src/hardware/rigol-ds/api.c
index 257bd11ee082df2d7eccfcc473562178380e4783..c25f9ef51ca0d39d5def1ff89939c2892ab5f45c 100644 (file)
--- a/src/hardware/rigol-ds/api.c
+++ b/src/hardware/rigol-ds/api.c
@@ -502,7 +502,7 @@ static int config_get(uint32_t key, GVariant **data, const struct sr_dev_inst *s
        const char *tmp_str;
        uint64_t samplerate;
        int analog_channel = -1;
-       float smallest_diff = 0.0000000001;
+       float smallest_diff = INFINITY;
        int idx = -1;
        unsigned i;