perf tools: Fix leaking rec_argv in error cases

Let's free the allocated rec_argv in case we return early, in order to
avoid leaking memory.

This adds free() at a few very similar places across the tree where it
was missing.

Signed-off-by: Martin Kepplinger <martink@posteo.de>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Martin kepplinger <martink@posteo.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20170913191419.29806-1-martink@posteo.de
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 ee8c6e8..967bd35 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -2078,6 +2078,7 @@ static int trace__record(struct trace *trace, int argc, const char **argv)
 			rec_argv[j++] = "syscalls:sys_enter,syscalls:sys_exit";
 		else {
 			pr_err("Neither raw_syscalls nor syscalls events exist.\n");
+			free(rec_argv);
 			return -1;
 		}
 	}