gfs2: Switch to wait_event in gfs2_logd

[ Upstream commit 6df373b0

 ]

In gfs2_logd(), switch from an open-coded wait loop to
wait_event_interruptible_timeout().

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Stable-dep-of: b74cd55a

 ("gfs2: low-memory forced flush fixes")
Signed-off-by: Sasha Levin <sashal@kernel.org>