buildroot

libusb-compat: fix a build issue with undefined PATH_MAX

libsigrok build failed because of PATH_MAX not being defined in usb.h.
On linux it is defined in linux/limits.h, but usb.h only includes
limit.h. Add a patch fixing the header in libusb-compat.

While we're at it: remove the patch numbering from previous patch.

Fixes: http://autobuild.buildroot.net/results/535/5353c2418c0c3311ef9ecb1f1ddc3ce769369b96/
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>