tree af1c042a8443e8313b2aa407b12d1f2f85c7775d
parent b832e9f03ac32cfe23b6962007f53d781d8231b9
author Chris Dickens <christopher.a.dickens@gmail.com> 1587072402 -0700
committer Chris Dickens <christopher.a.dickens@gmail.com> 1587072402 -0700

libusb.h: Make C-preprocessor checks consistent and safe

Instead of mixing 'ifdef' with 'if defined(...)', use the latter
everywhere.

Check whether the __GNUC__ macro is defined before using it to avoid
compiler warnings.

Signed-off-by: Chris Dickens <christopher.a.dickens@gmail.com>