[tip:perf/core] perf probe: Fix to return 0 when positive value returned

[tip-bot for Masami Hiramatsu <tipbot@zytor.com>]

Commit-ID:  9bc9f3b6800e8de16f40a2da1d6ded3a391ea01a
Gitweb:     http://git.kernel.org/tip/9bc9f3b6800e8de16f40a2da1d6ded3a391ea01a
Author:     Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
AuthorDate: Wed, 6 May 2015 21:46:45 +0900
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Fri, 8 May 2015 16:05:01 -0300

perf probe: Fix to return 0 when positive value returned

Fix to return 0 when positive value returned from probe command.

At least --vars can returns a positive value if it found a point.
  ----
  # perf probe --vars vfs_read && echo succeeded! || echo failed!
  Available variables at vfs_read
          @<vfs_read+0>
                  char*   buf
                  loff_t* pos
                  size_t  count
                  struct file*    file
  failed!
  ----

This fixes above problem.
  ----
  # perf probe --vars vfs_read && echo succeeded! || echo failed!
  Available variables at vfs_read
          @<vfs_read+0>
                  char*   buf
                  loff_t* pos
                  size_t  count
                  struct file*    file
  succeeded!
  ----

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20150506124645.4961.56973.stgit@localhost.localdomain
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/builtin-probe.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/builtin-probe.c b/tools/perf/builtin-probe.c
index 53d475b..9c4cf5e 100644
--- a/tools/perf/builtin-probe.c
+++ b/tools/perf/builtin-probe.c
@@ -523,5 +523,5 @@ int cmd_probe(int argc, const char **argv, const char *prefix)
 		cleanup_params();
 	}
 
-	return ret;
+	return ret < 0 ? ret : 0;
 }