are getting ENOSPC errors on writes. When we fail to allocate space for
indirect blocks in xfs_bmapi() make sure we release the direct block
allocation before returning.

SGI-PV: 938502
SGI-Modid: xfs-linux:xfs-kern:22986a
Signed-off-by: NDavid Chinner <dgc@sgi.com>
Signed-off-by: NNathan Scott <nathans@sgi.com>