perf tools: Fix AAAAARGH64 memory barriers

Someone got the load and store barriers mixed up for AAAAARGH64.  Turn
them the right side up.
Reported-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Fixes: a94d342b ("tools/perf: Add required memory barriers")
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Will Deacon <will.deacon@arm.com>
Link: http://lkml.kernel.org/r/20140124154002.GF31570@twins.programming.kicks-ass.netSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/perf.h

@@ -100,8 +100,8 @@
 
 #ifdef __aarch64__
 #define mb()		asm volatile("dmb ish" ::: "memory")
-#define wmb()		asm volatile("dmb ishld" ::: "memory")
-#define rmb()		asm volatile("dmb ishst" ::: "memory")
+#define wmb()		asm volatile("dmb ishst" ::: "memory")
+#define rmb()		asm volatile("dmb ishld" ::: "memory")
 #define cpu_relax()	asm volatile("yield" ::: "memory")
 #endif