configure.ac: Fix checks for cross-compiles.

When checking architecture-specific things, always check $host, i.e. the
architecture we're building _for_, not the one we happen to build _on_.

E.g. when cross-compiling _for_ Android (or Windows or others) it's important
to check for Android in $host; whether we happen to cross-compile _on_ a Linux
or Windows or OpenBSD or FreeBSD machine ($build) doesn't matter, only the
fact that we compile _for_ Android is important for most checks.

diff --git a/configure.ac b/configure.ac
index 4720f6e96a11a790d660277bf9ba58ea35d4c682..e3fd71752e814f76afb92420c80943f2ce11ffc6 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -209,7 +209,7 @@ PKG_CHECK_MODULES([libzip], [libzip >= 0.8],
 
 # libusb-1.0 is only needed for some hardware drivers. Disable the respective
 # drivers if it is not found.
-case "$build" in
+case "$host" in
 *freebsd*)
        # FreeBSD comes with an "integrated" libusb-1.0-style USB API.
        # This means libusb-1.0 is always available, no need to check for it,
@@ -266,7 +266,7 @@ AM_CONDITIONAL(HAVE_CHECK, test x"$have_check" = "xyes")
 # The Rigol DS1xx2 driver currently uses the Linux kernel usbtmc module
 # (though it is planned to rewrite the driver to be portable later).
 # Thus, it will be disabled for non-Linux builds for now.
-case "$build" in
+case "$host" in
 *linux*)
        # Do nothing. Whether the driver is enabled is determined by the
        # previous --enable-all-drivers/--disable-all-drivers and/or any