gfs2: Minor gfs2_glock_nq_m cleanup

Add state and flags arguments to gfs2_rlist_alloc() to make it somewhat more
obvious which state and flags an rlist uses.  With that, stop knocking off
flags in gfs2_glock_nq_m() and its nq_m_sync() helper that are never set in the
first place.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>