gfs2: No longer thaw filesystems during a withdraw

gfs2: No longer thaw filesystems during a withdraw

Previously, when a withdraw occurred, we would wait for another node to
recover our journal.  This also meant that frozen filesystem needed to
be thawed because otherwise, other nodes wouldn't be able to recover the
filesystem.  With the reversal of commit 601ef0d52e96 ("gfs2: Force
withdraw to replay journals and wait for it to finish"), we are no
longer waiting for journal recovery during a withdraw, so we no longer
need to thaw frozen filesystems, either.  This also fixes a potential
deadlock reported by lockdep when running xfstest generic/108.

In addition, there is nothing left in do_withdraw() that would require
taking sd_freeze_mutex, so don't bother taking that lock there anymore.

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