tools/perf: Clean up util/include/linux/compiler.h

Use the standard CPP style we use in the kernel:

 #ifndef foo
 # define foo bar
 #endif

Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/n/tip-iqyVrrHqpn0eiwenvgwrh8lf@git.kernel.orgSigned-off-by: Ingo Molnar <mingo@kernel.org>

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

@@ -2,20 +2,25 @@
 #define _PERF_LINUX_COMPILER_H_
 
 #ifndef __always_inline
-#define __always_inline	inline
+# define __always_inline	inline __attribute__((always_inline))
 #endif
+
 #define __user
+
 #ifndef __attribute_const__
-#define __attribute_const__
+# define __attribute_const__
 #endif
 
 #ifndef __maybe_unused
-#define __maybe_unused		__attribute__((unused))
+# define __maybe_unused		__attribute__((unused))
+#endif
+
+#ifndef __packed
+# define __packed		__attribute__((__packed__))
 #endif
-#define __packed	__attribute__((__packed__))
 
 #ifndef __force
-#define __force
+# define __force
 #endif
 
 #endif