xfs: don't bother returning errors from xfs_file_release

xfs: don't bother returning errors from xfs_file_release

While ->release returns int, the only caller ignores the return value.
As we're only doing cleanup work there isn't much of a point in
return a value to start with, so just document the situation instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>