[MUTEX]: linux/mutex.h needs linux/linkage.h too

Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/mutex.h

@@ -12,6 +12,7 @@
 
 #include <linux/list.h>
 #include <linux/spinlock_types.h>
+#include <linux/linkage.h>
 
 #include <asm/atomic.h>