[PATCH] fix alpha breakage

barrier.h uses barrier() in non-SMP case.  And doesn't include compiler.h.

Cc: Al Viro <viro@ftp.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

include/asm-alpha/barrier.h

@@ -1,6 +1,8 @@
 #ifndef __BARRIER_H
 #define __BARRIER_H
 
+#include <asm/compiler.h>
+
 #define mb() \
 __asm__ __volatile__("mb": : :"memory")