LU-18141 obdclass: don't check for NULL before free'ing

LU-18141 obdclass: don't check for NULL before free'ing

The common free'ing macros already check for NULL,
so we don't need to explicitly check this beforehand.

The patch has been generated with the coccinelle script below.

@@
expression E;
@@
- if (E != NULL)
(
  OBD_FREE_PTR(E);
|
  OBD_FREE(E, ...);
|
  LIBCFS_FREE(E, ...);
|
  CFS_FREE_PTR(E);
|
  CFS_FREE_PTR_ARRAY(E, ...);
)

Test-Parameters: trivial
Signed-off-by: Timothy Day <timday@amazon.com>
Change-Id: Ie5d5567fecc1f421fb0894816c880b41ea93843b
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/56042
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Arshad Hussain <arshad.hussain@aeoncomputing.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Reviewed-by: Oleg Drokin <green@whamcloud.com>