drm/radeon/kms: signed fix for evergreen thermal

temperature is signed.

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/radeon/evergreen.c b/drivers/gpu/drm/radeon/evergreen.c
index 86157b1..7e3d96e 100644
--- a/drivers/gpu/drm/radeon/evergreen.c
+++ b/drivers/gpu/drm/radeon/evergreen.c
@@ -88,7 +88,8 @@
 /* get temperature in millidegrees */
 int evergreen_get_temp(struct radeon_device *rdev)
 {
-	u32 temp, toffset, actual_temp = 0;
+	u32 temp, toffset;
+	int actual_temp = 0;
 
 	if (rdev->family == CHIP_JUNIPER) {
 		toffset = (RREG32(CG_THERMAL_CTRL) & TOFFSET_MASK) >>