ext4: remove unnecessary lock/unlock of i_block_reservation_lock

This is a leftover of commit 71d4f7d032149b935a26eb3ff85c6c837f3714e1

Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Lukas Czerner <lczerner@redhat.com>

fs/ext4/balloc.c

@@ -640,8 +640,6 @@ ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode,
 	 * fail EDQUOT for metdata, but we do account for it.
 	 */
 	if (!(*errp) && (flags & EXT4_MB_DELALLOC_RESERVED)) {
-		spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
-		spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
 		dquot_alloc_block_nofail(inode,
 				EXT4_C2B(EXT4_SB(inode->i_sb), ar.len));
 	}