x86: remove volatile keyword from clflush.

the p parameter is an explicit memory reference, and is
enough to prevent gcc to being nasty here. The volatile
seems completely not needed.
Signed-off-by: NGlauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

include/asm-x86/system_32.h

@@ -161,7 +161,7 @@ static inline void native_wbinvd(void)
 	asm volatile("wbinvd": : :"memory");
 }
 
-static inline void clflush(volatile void *__p)
+static inline void clflush(void *__p)
 {
 	asm volatile("clflush %0" : "+m" (*(char __force *)__p));
 }