perf trace: Add fallback definition of EFD_SEMAPHORE

glibc 2.17 is missing this on sparc, despite the fact that it's not
architecture-specific.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Fixes: 49af9e93adfa ('perf trace: Beautify eventfd2 'flags' arg')
Cc: <stable@vger.kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1391648435.3003.100.camel@deadeye.wl.decadent.org.uk
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index 896f270..619d11c 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -37,6 +37,10 @@
 # define MADV_UNMERGEABLE	13
 #endif
 
+#ifndef EFD_SEMAPHORE
+# define EFD_SEMAPHORE		1
+#endif
+
 struct tp_field {
 	int offset;
 	union {