cgroup: Resource leak (RESOURCE_LEAK)

CID 302717 (#2 of 2): Resource leak (RESOURCE_LEAK)
 Variable dirnew going out of scope leaks the storage it points to.

Signed-off-by: Adrian Reber <areber@redhat.com>

criu/cgroup.c

@@ -1906,6 +1906,7 @@ static int rewrite_cgsets(CgroupEntry *cge, char **controllers, int n_controller
 						    cg->path + dirlen + 1);
 				if (!cg->path) {
 					cg->path = prev;
+					xfree(dirnew);
 					return -ENOMEM;
 				}
 				xfree(prev);