gfs2: Fix quota=quiet oversight

Patch eef46ab7 introduced a new gfs2 quota=quiet mount option.
Checks for the new option were added to quota.c, but a check in
gfs2_quota_lock_check() was overlooked.  This patch adds the missing
check.

Fixes: eef46ab7 ("gfs2: Introduce new quota=quiet mount option")
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>