LU-216 ldiskfs: use proper arguments for ldiskfs_free_blocks

LU-216 ldiskfs: use proper arguments for ldiskfs_free_blocks

In ldiskfs_ext_new_extent_cb(), the extent length argument
is confusingly converted from le16 using cpu_to_le16() instead
of le16_to_cpu().  While this is functionally correct, it is
semantically incorrect and can confuse static code analysis.

Signed-off-by: Andrew Perepechko <andrew_perepechko@xyratex.com>
Signed-off-by: Andreas Dilger <andreas.dilger@intel.com>
Change-Id: I8b3a684677c66d96fe4828fa771fc309c21755b8
Reviewed-on: http://review.whamcloud.com/1720
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Jian Yu <jian.yu@intel.com>
Reviewed-by: John L. Hammond <john.hammond@intel.com>