staging, rtl8192e, LLVMLinux: Remove unused inline prototype

rtllib_probe_req is defined as "static inline" in rtllib_softmac.c however it
is declared differently as "extern inline" in rtllib_softmac.h. Since it isn't
used outside of the scope of rtllib_softmac, it makes sense to remove the
incorrect declaration.

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>