drivers/amdgpu: Use canonical form in branch predicates

Found-by: Coccinelle
Signed-off-by: Edward O'Callaghan <funfunctor@folklore1984.net>
Reviewed-by: Tom St Denis <tom.stdenis@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c
index 99ca75b..2b6afe1 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c
@@ -352,22 +352,22 @@
 	uint16_t tmp, bios_header_start;
 
 	r = amdgpu_atrm_get_bios(adev);
-	if (r == false)
+	if (!r)
 		r = amdgpu_acpi_vfct_bios(adev);
-	if (r == false)
+	if (!r)
 		r = igp_read_bios_from_vram(adev);
-	if (r == false)
+	if (!r)
 		r = amdgpu_read_bios(adev);
-	if (r == false) {
+	if (!r) {
 		r = amdgpu_read_bios_from_rom(adev);
 	}
-	if (r == false) {
+	if (!r) {
 		r = amdgpu_read_disabled_bios(adev);
 	}
-	if (r == false) {
+	if (!r) {
 		r = amdgpu_read_platform_bios(adev);
 	}
-	if (r == false || adev->bios == NULL) {
+	if (!r || adev->bios == NULL) {
 		DRM_ERROR("Unable to locate a BIOS ROM\n");
 		adev->bios = NULL;
 		return false;