loadpin: stop using bdevname

Use the %pg format specifier to save on stack consuption and code size.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220512062014.1826835-1-hch@lst.de

security/loadpin/loadpin.c

@@ -78,11 +78,8 @@ static void check_pinning_enforcement(struct super_block *mnt_sb)
 	 * device, allow sysctl to change modes for testing.
 	 */
 	if (mnt_sb->s_bdev) {
-		char bdev[BDEVNAME_SIZE];
-
 		ro = bdev_read_only(mnt_sb->s_bdev);
-		bdevname(mnt_sb->s_bdev, bdev);
-		pr_info("%s (%u:%u): %s\n", bdev,
+		pr_info("%pg (%u:%u): %s\n", mnt_sb->s_bdev,
 			MAJOR(mnt_sb->s_bdev->bd_dev),
 			MINOR(mnt_sb->s_bdev->bd_dev),
 			ro ? "read-only" : "writable");