zfs, zpool: safe_malloc() duplicate argv

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #13259

cmd/zpool/zpool_main.c

@@ -10924,7 +10924,7 @@ main(int argc, char **argv)
 	 * Many commands modify input strings for string parsing reasons.
 	 * We create a copy to protect the original argv.
 	 */
-	newargv = malloc((argc + 1) * sizeof (newargv[0]));
+	newargv = safe_malloc((argc + 1) * sizeof (newargv[0]));
 	for (i = 0; i < argc; i++)
 		newargv[i] = strdup(argv[i]);
 	newargv[argc] = NULL;