perf kmem: Fill in the missing session freeing after an error occurs

When an error occurs an error value is just returned without freeing the
session. So allocating and freeing session have to be matched as a pair
even if an error occurs.
Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1435652124-22414-3-git-send-email-treeze.taeung@gmail.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-kmem.c

@@ -1916,7 +1916,7 @@ int cmd_kmem(int argc, const char **argv, const char *prefix __maybe_unused)
 		if (!perf_evlist__find_tracepoint_by_name(session->evlist,
 							  "kmem:kmalloc")) {
 			pr_err(errmsg, "slab", "slab");
-			return -1;
+			goto out_delete;
 		}
 	}
 
@@ -1927,7 +1927,7 @@ int cmd_kmem(int argc, const char **argv, const char *prefix __maybe_unused)
 							     "kmem:mm_page_alloc");
 		if (evsel == NULL) {
 			pr_err(errmsg, "page", "page");
-			return -1;
+			goto out_delete;
 		}
 
 		kmem_page_size = pevent_get_page_size(evsel->tp_format->pevent);