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

LU-18141 ptlrpc: 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: Ia436882262a14fda2486b36999c2189f976b047a
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/56046
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: jsimmons <jsimmons@infradead.org>
Reviewed-by: Arshad Hussain <arshad.hussain@aeoncomputing.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>