VFS: fix unused variable warning

Commit 33dcdac2 ("kill ->put_inode")
removed the final use of i_op->put_inode, but left the now totally
unused "op" variable in iput().

Get rid of it.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/inode.c

@@ -1149,8 +1149,6 @@ static inline void iput_final(struct inode *inode)
 void iput(struct inode *inode)
 {
 	if (inode) {
-		const struct super_operations *op = inode->i_sb->s_op;
-
 		BUG_ON(inode->i_state == I_CLEAR);
 
 		if (atomic_dec_and_lock(&inode->i_count, &inode_lock))