perf tools: Convert to BACKTRACE_SUPPORT

For building perf without stack backtrace debug, we can set
NO_BACKTRACE=1 as a argument of make.  It then defines NO_BACKTRACE
macro for C code to do the proper handling.  However it usually used in
a negative semantics - e.g. #ifndef - so we saw double negations which
can be misleading.  Convert it to a positive form to make it more
readable and add _SUPPORT suffix for consistency.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Irina Tirdea <irina.tirdea@gmail.com>
Cc: Irina Tirdea <irina.tirdea@intel.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1349109171-1942-1-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c
index 2055cf38041c..99664598bc1a 100644
--- a/tools/perf/util/util.c
+++ b/tools/perf/util/util.c
@@ -1,7 +1,7 @@
 #include "../perf.h"
 #include "util.h"
 #include <sys/mman.h>
-#ifndef NO_BACKTRACE
+#ifdef BACKTRACE_SUPPORT
 #include <execinfo.h>
 #endif
 #include <stdio.h>
@@ -165,7 +165,7 @@ size_t hex_width(u64 v)
 }
 
 /* Obtain a backtrace and print it to stdout. */
-#ifndef NO_BACKTRACE
+#ifdef BACKTRACE_SUPPORT
 void dump_stack(void)
 {
         void *array[16];