xfs: remove the unusued tmp_logflags variable in xfs_bmapi_allocate

tmp_logflags is initialized to 0 and then ORed into bma->logflags, which
isn't actually doing anything.

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>