Rearrange the code to avoid the conditional locking around the flist_locked
variable.  This means we lose a (rather pointless) assert, and hold the
freelist lock a bit longer for one corner case.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NBen Myers <bpm@sgi.com>