drm/nouveau/acr: Use kmemdup instead of kmalloc and memcpy

Fixes coccicheck warning:

drivers/gpu/drm/nouveau/nvkm/subdev/acr/hsfw.c:103:23-30: WARNING opportunity for kmemdup
drivers/gpu/drm/nouveau/nvkm/subdev/acr/hsfw.c:113:22-29: WARNING opportunity for kmemdup

Fixes: 22dcda45a3 ("drm/nouveau/acr: implement new subdev to replace "secure boot"")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zou Wei <zou_wei@huawei.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nvkm/subdev/acr/hsfw.c

@@ -100,25 +100,21 @@ nvkm_acr_hsfw_load_image(struct nvkm_acr *acr, const char *name, int ver,
 	hsfw->data_size = lhdr->data_size;
 
 	hsfw->sig.prod.size = fwhdr->sig_prod_size;
-	hsfw->sig.prod.data = kmalloc(hsfw->sig.prod.size, GFP_KERNEL);
+	hsfw->sig.prod.data = kmemdup(fw->data + fwhdr->sig_prod_offset + sig,
+				      hsfw->sig.prod.size, GFP_KERNEL);
 	if (!hsfw->sig.prod.data) {
 		ret = -ENOMEM;
 		goto done;
 	}
 
-	memcpy(hsfw->sig.prod.data, fw->data + fwhdr->sig_prod_offset + sig,
-	       hsfw->sig.prod.size);
-
 	hsfw->sig.dbg.size = fwhdr->sig_dbg_size;
-	hsfw->sig.dbg.data = kmalloc(hsfw->sig.dbg.size, GFP_KERNEL);
+	hsfw->sig.dbg.data = kmemdup(fw->data + fwhdr->sig_dbg_offset + sig,
+				     hsfw->sig.dbg.size, GFP_KERNEL);
 	if (!hsfw->sig.dbg.data) {
 		ret = -ENOMEM;
 		goto done;
 	}
 
-	memcpy(hsfw->sig.dbg.data, fw->data + fwhdr->sig_dbg_offset + sig,
-	       hsfw->sig.dbg.size);
-
 	hsfw->sig.patch_loc = loc;
 done:
 	nvkm_firmware_put(fw);