headers_check.pl: disallow extern's
headers_check.pl: disallow extern's

Since prototypes with "extern" refer to kernel functions, they make no
sense in userspace, so reject them automatically.

Signed-off-by: Mike Frysinger <8f3f75c74bd5184edcfa6534cab3c13a00a2f794@gentoo.org>
[sam: made it into a warning]
Signed-off-by: Sam Ravnborg <f16bed56189e249fe4ca8ed10a1ecae60e8ceac0@ravnborg.org>

KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas