perf tools: Fix a dso open fail message

It's not related to mmap, remove it from the message.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1422585209-32742-3-git-send-email-namhyung@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/dso.c

@@ -240,7 +240,7 @@ static int do_open(char *name)
 		if (fd >= 0)
 			return fd;
 
-		pr_debug("dso open failed, mmap: %s\n",
+		pr_debug("dso open failed: %s\n",
 			 strerror_r(errno, sbuf, sizeof(sbuf)));
 		if (!dso__data_open_cnt || errno != EMFILE)
 			break;