selftests/hid: fix bpf compilations due to -fms-extensions

selftests/hid: fix bpf compilations due to -fms-extensions

Similar to commit 835a50753579 ("selftests/bpf: Add -fms-extensions to
bpf build flags") and commit 639f58a0f480 ("bpftool: Fix build warnings
due to MS extensions")

The kernel is now built with -fms-extensions, therefore
generated vmlinux.h contains types like:
struct slab {
   ..
   struct freelist_counters;
};

Use -fms-extensions and -Wno-microsoft-anon-tag flags
to build bpf programs that #include "vmlinux.h"

Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>