configfs_do_depend_item(): pass configfs_dirent instead of dentry

configfs_do_depend_item(): pass configfs_dirent instead of dentry

Again, the only thing it uses the argument for is its ->d_fsdata
and callers already have that - as the matter of fact, they are
passing ->s_dentry of that configfs_dirent, so that the function
could get it back as ->d_fsdata of that.  With nothing else in
dentry even looked at...

configfs_dirent in question is a directory one - in this case those
are subdirectories of root (aka roots of "subsystem" trees).

Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>