Cleanup umem driver: fix most checkpatch warnings, conform to kernel

coding style.

  linux-2.6.24-rc5-git3> checkpatch.pl-next  patches/block-umem-ckpatch.patch
  total: 0 errors, 5 warnings, 530 lines checked

All of these are line-length warnings.

Only change in generated object file is due to not initializing a
static global variable to 0.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>