perf tools: Use for_each_set_bit() to iterate over feature flags

This patch introduces the for_each_set_bit() macro and modifies feature
implementation to use it.

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1323248577-11268-8-git-send-email-robert.richter@amd.com
Signed-off-by: Robert Richter <robert.richter@amd.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/header.h b/tools/perf/util/header.h
index 09365b3..ac4ec95 100644
--- a/tools/perf/util/header.h
+++ b/tools/perf/util/header.h
@@ -10,7 +10,8 @@
 #include <linux/bitmap.h>
 
 enum {
-	HEADER_TRACE_INFO = 1,
+	HEADER_RESERVED		= 0,	/* always cleared */
+	HEADER_TRACE_INFO	= 1,
 	HEADER_BUILD_ID,
 
 	HEADER_HOSTNAME,
@@ -27,10 +28,9 @@
 	HEADER_NUMA_TOPOLOGY,
 
 	HEADER_LAST_FEATURE,
+	HEADER_FEAT_BITS	= 256,
 };
 
-#define HEADER_FEAT_BITS			256
-
 struct perf_file_section {
 	u64 offset;
 	u64 size;