VFS: Remove detached-dentry counter from shrink_dcache_for_umount_subtree()

Remove the detached-dentry counter from shrink_dcache_for_umount_subtree() as
the value it computes is no longer used as of commit
312d3ca856d369bb04d0443846b85b4cdde6fa8a which made the nr_dentry counters
summed per-CPU rather than global atomic.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/dcache.c

@@ -828,7 +828,6 @@ EXPORT_SYMBOL(shrink_dcache_sb);
 static void shrink_dcache_for_umount_subtree(struct dentry *dentry)
 {
 	struct dentry *parent;
-	unsigned detached = 0;
 
 	BUG_ON(!IS_ROOT(dentry));
 
@@ -892,8 +891,6 @@ static void shrink_dcache_for_umount_subtree(struct dentry *dentry)
 				spin_unlock(&parent->d_lock);
 			}
 
-			detached++;
-
 			inode = dentry->d_inode;
 			if (inode) {
 				dentry->d_inode = NULL;