ocfs2: fix some small problems

ocfs2: fix some small problems

First, move setting fe_done = 1 in spin lock, avoid bring any potential
race condition.

Second, tune mlog message level from ERROR to NOTICE, since the message
should not belong to error message.

Third, tune errno to -EAGAIN when file check queue is full, this errno
is more appropriate in the case.

Link: http://lkml.kernel.org/r/1495611866-27360-3-git-send-email-ghe@suse.com
Signed-off-by: Gang He <ghe@suse.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <jiangqi903@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>