target/iblock: Use match_strlcpy for Opt_udev_path string assignment

Following commit dbc6e022 from Al Viro for fileio, go ahead and make
Opt_udev_path within iblock_set_configfs_dev_params use match_strlcpy
instead of the match_strdup -> snprintf -> kfree equivalent.
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

drivers/target/target_core_iblock.c

@@ -454,14 +454,11 @@ static ssize_t iblock_set_configfs_dev_params(struct se_hba *hba,
 				ret = -EEXIST;
 				goto out;
 			}
-			arg_p = match_strdup(&args[0]);
-			if (!arg_p) {
-				ret = -ENOMEM;
+			if (match_strlcpy(ib_dev->ibd_udev_path, &args[0],
+				SE_UDEV_PATH_LEN) == 0) {
+				ret = -EINVAL;
 				break;
 			}
-			snprintf(ib_dev->ibd_udev_path, SE_UDEV_PATH_LEN,
-					"%s", arg_p);
-			kfree(arg_p);
 			pr_debug("IBLOCK: Referencing UDEV path: %s\n",
 					ib_dev->ibd_udev_path);
 			ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH;