staging, rtl8192e, LLVMLinux: Change extern inline to static inline

With compilers which follow the C99 standard (like modern versions of gcc and
clang), "extern inline" does the opposite thing from older versions of gcc
(emits code for an externally linkable version of the inline function).

"static inline" does the intended behavior in all cases instead.

Signed-off-by: Behan Webster <behanw@converseincode.com>
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>