ufs_extend_tail(): fix the braino in calling conventions of ufs_new_fragments()

commit 940ef1a0ed939c2ca029fca715e25e7778ce1e34 upstream.

... and it really needs splitting into "new" and "extend" cases, but that's for
later

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>