isofs: release buffer head before return

Release the buffer_head before returning error code in
do_isofs_readdir() and isofs_find_entry().

Fixes: 2deb1acc653c ("isofs: fix access to unallocated memory when reading corrupted filesystem")
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Pan Bian <[e-mail]>
Signed-off-by: Jan Kara <[e-mail]>

fs/isofs/dir.c

···
 			printk(KERN_NOTICE "iso9660: Corrupted directory entry"
 			       " in block %lu of inode %lu\n", block,
 			       inode->i_ino);
+			brelse(bh);
 			return -EIO;
 		}
 

fs/isofs/namei.c

···
 			printk(KERN_NOTICE "iso9660: Corrupted directory entry"
 			       " in block %lu of inode %lu\n", block,
 			       dir->i_ino);
+			brelse(bh);
 			return 0;
 		}