drm/nouveau/bios/power_budget: Move an expression into a macro call parameter...

drm/nouveau/bios/power_budget: Move an expression into a macro call parameter in nvbios_power_budget_header()

The address of a data structure member was determined before
a corresponding null pointer check in the implementation of
the function “nvbios_power_budget_header”.

Thus avoid the risk for undefined behaviour by moving the usage
of an expression into a parameter for a macro call in one if branch.

This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Reviewed-by: Karol Herbst <kherbst@redhat.com>
Signed-off-by: Karol Herbst <kherbst@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/529fe82e-59f0-71a2-1e33-b051f833b67c@web.de

drivers/gpu/drm/nouveau/nvkm/subdev/bios/power_budget.c

@@ -59,7 +59,6 @@ int
 nvbios_power_budget_header(struct nvkm_bios *bios,
                            struct nvbios_power_budget *budget)
 {
-	struct nvkm_subdev *subdev = &bios->subdev;
 	u8 ver, hdr, cnt, len, cap_entry;
 	u32 header;
 
@@ -82,7 +81,7 @@ nvbios_power_budget_header(struct nvkm_bios *bios,
 	}
 
 	if (cap_entry >= cnt && cap_entry != 0xff) {
-		nvkm_warn(subdev,
+		nvkm_warn(&bios->subdev,
 		          "invalid cap_entry in power budget table found\n");
 		budget->cap_entry = 0xff;
 		return -EINVAL;