drm/xe/pxp: Don't use 0 to indicate NULL

Explicitly using NULL is the correct approach.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202502050322.VUBMyUHc-lkp@intel.com/
Fixes: dcdd6b8 ("drm/xe/pxp: Allocate PXP execution resources")
Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250204200144.1445800-1-daniele.ceraolospurio@intel.com

Author: dceraolo

drivers/gpu/drm/xe/xe_pxp_submit.c

@@ -54,7 +54,7 @@ static int allocate_vcs_execution_resources(struct xe_pxp *pxp)
 	 * Each termination is 16 DWORDS, so 4K is enough to contain a
 	 * termination for each sessions.
 	 */
-	bo = xe_bo_create_pin_map(xe, tile, 0, SZ_4K, ttm_bo_type_kernel,
+	bo = xe_bo_create_pin_map(xe, tile, NULL, SZ_4K, ttm_bo_type_kernel,
 				  XE_BO_FLAG_SYSTEM | XE_BO_FLAG_PINNED | XE_BO_FLAG_GGTT);
 	if (IS_ERR(bo)) {
 		err = PTR_ERR(bo);