perf tools: Move __used from perf.h to linux/compiler.h

Just like in the kernel and also to remove the need to include
perf.h in the symbol subsystem.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1269557941-15617-4-git-send-email-acme@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

tools/perf/perf.h

@@ -106,8 +106,6 @@ static inline unsigned long long rdclock(void)
 #define __user
 #define asmlinkage
 
-#define __used		__attribute__((__unused__))
-
 #define unlikely(x)	__builtin_expect(!!(x), 0)
 #define min(x, y) ({				\
 	typeof(x) _min1 = (x);			\

tools/perf/util/include/linux/compiler.h

@@ -7,4 +7,6 @@
 #define __user
 #define __attribute_const__
 
+#define __used		__attribute__((__unused__))
+
 #endif