misc: cxl: Fix possible null pointer dereference

It is not safe to dereference an object before a null test. It is
not needed and just remove them. Ftrace can be used instead.

Signed-off-by: zhong jiang <zhongjiang@huawei.com>
Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: Frederic Barrat <fbarrat@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/misc/cxl/guest.c

@@ -1018,8 +1018,6 @@ err1:
 
 void cxl_guest_remove_afu(struct cxl_afu *afu)
 {
-	pr_devel("in %s - AFU(%d)\n", __func__, afu->slice);
-
 	if (!afu)
 		return;