drm/radeon/kms: Hide debugging message

Use the proper macro to issue the debugging message in
radeon_atif_call(). Otherwise we spam the log of many systems with a
message which looks like an error message of unknown origin, and could
thus confuse the user. Commit dc77de12
was a first step in this direction, but was not sufficient IMHO.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/radeon/radeon_acpi.c

@@ -35,7 +35,8 @@ static int radeon_atif_call(acpi_handle handle)
 
 	/* Fail only if calling the method fails and ATIF is supported */
 	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
-		printk(KERN_DEBUG "failed to evaluate ATIF got %s\n", acpi_format_exception(status));
+		DRM_DEBUG_DRIVER("failed to evaluate ATIF got %s\n",
+				 acpi_format_exception(status));
 		kfree(buffer.pointer);
 		return 1;
 	}