perf tools: Protect header files with a consistent style

There was a colorful mix of header guards - standardize them.

Signed-off-by: John Kacur <jkacur@redhat.com>
LKML-Reference: <alpine.LFD.2.00.0909241756530.11383@localhost.localdomain>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

tools/perf/util/event.h

@@ -1,5 +1,6 @@
 #ifndef __PERF_RECORD_H
 #define __PERF_RECORD_H
+
 #include "../perf.h"
 #include "util.h"
 #include <linux/list.h>
@@ -101,4 +102,4 @@ struct map *map__clone(struct map *self);
 int map__overlap(struct map *l, struct map *r);
 size_t map__fprintf(struct map *self, FILE *fp);
 
-#endif
+#endif /* __PERF_RECORD_H */