LU-9859 gss: replace cfs_size_roundXX macros.

LU-9859 gss: replace cfs_size_roundXX macros.

Many of the cfs_size_roundX() macros are not even used so delete
them. Replace cfs_size_round4() uses in the GSS layer with
round_up(var, 4);

Change-Id: Id35f0f7b60f8d00f425d9b15d2a76aa4d0fa5f2f
Signed-off-by: James Simmons <jsimmons@infradead.org>
Reviewed-on: https://review.whamcloud.com/45584
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Sebastien Buisson <sbuisson@ddn.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Arshad Hussain <arshad.hussain@aeoncomputing.com>