crtools: Fix potential nil dereference

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

crtools.c

@@ -551,6 +551,8 @@ int main(int argc, char *argv[], char *envp[])
 		}
 
 		opts.exec_cmd = xmalloc((argc - optind) * sizeof(char *));
+		if (!opts.exec_cmd)
+			return 1;
 		memcpy(opts.exec_cmd, &argv[optind + 1], (argc - optind - 1) * sizeof(char *));
 		opts.exec_cmd[argc - optind - 1] = NULL;
 	} else if (optind + 1 != argc) {