LU-16518 osc: fix unused-but-set-variable warnings

LU-16518 osc: fix unused-but-set-variable warnings

When CONFIG_CRC_T10DIF=n and osc_checksum_bulk_t10pi() is
a macro, Clang generates compiler warnings for some of the
arguments - since they are not used elsewhere. Silence this
by creating a proper function.

Test-Parameters: trivial
Signed-off-by: Timothy Day <timday@amazon.com>
Change-Id: I502dcf1764602711fcf2cf3553ad6d2f4fed3f14
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/58182
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Max Wang <wamax@amazon.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>