UDF: During mount free lvid_bh before rescanning with different blocksize

If s_lvid_bh is not freed and set to NULL before re-scanning partition
with default block size, we might end up using wrong lvid in case
s_lvid_bh is not updated in udf_load_logicalvolint during rescan.
Signed-off-by: Ashish Sangwan <ashish.sangwan2@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>

fs/udf/super.c

@@ -2000,6 +2000,8 @@ static int udf_fill_super(struct super_block *sb, void *options, int silent)
 			if (!silent)
 				pr_notice("Rescanning with blocksize %d\n",
 					  UDF_DEFAULT_BLOCKSIZE);
+			brelse(sbi->s_lvid_bh);
+			sbi->s_lvid_bh = NULL;
 			uopt.blocksize = UDF_DEFAULT_BLOCKSIZE;
 			ret = udf_load_vrs(sb, &uopt, silent, &fileset);
 		}