xfs: move xfs_inew_wait call into xfs_dqrele_inode

Move the INEW wait into xfs_dqrele_inode so that we can drop the
iter_flags parameter in the next patch.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>