perf kmem: Fix memory leak in compact_gfp_flags()

The memory @orig_flags is allocated by strdup(), it is freed on the
normal path, but leak to free on the error path.

Fix this by adding free(orig_flags) on the error path.

Fixes: 0e11115644 ("perf kmem: Print gfp flags in human readable string")
Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Feilong Lin <linfeilong@huawei.com>
Cc: Hu Shiyuan <hushiyuan@huawei.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/f9e9f458-96f3-4a97-a1d5-9feec2420e07@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-kmem.c

@@ -691,6 +691,7 @@ static char *compact_gfp_flags(char *gfp_flags)
 			new = realloc(new_flags, len + strlen(cpt) + 2);
 			if (new == NULL) {
 				free(new_flags);
+				free(orig_flags);
 				return NULL;
 			}