Fix build error of CVE-2021-0904

Change-Id: I6615d79fae19bf480492505e6d4aeccb448aa68f
diff --git a/drivers/gpu/msm/kgsl_iommu.c b/drivers/gpu/msm/kgsl_iommu.c
index 6c5bcb9..0bb24d6 100644
--- a/drivers/gpu/msm/kgsl_iommu.c
+++ b/drivers/gpu/msm/kgsl_iommu.c
@@ -828,7 +828,7 @@
 	if (context != NULL) {
 		/* save pagefault timestamp for GFT */
 		set_bit(KGSL_CONTEXT_PRIV_PAGEFAULT, &context->priv);
-		pid = context->proc_priv->pid;
+		pid = pid_nr(context->proc_priv->pid);
 	}
 
 	ctx->fault = 1;