drm/nv50/disp: silence compiler warning

NFI why this only started appearing now.  The use of the uninitialised var
can't actually happen, so perhaps my compiler just got stupider.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nv50_display.c

@@ -616,7 +616,7 @@ nv50_display_unk10_handler(struct drm_device *dev)
 	struct drm_nouveau_private *dev_priv = dev->dev_private;
 	struct nv50_display *disp = nv50_display(dev);
 	u32 unk30 = nv_rd32(dev, 0x610030), mc;
-	int i, crtc, or, type = OUTPUT_ANY;
+	int i, crtc, or = 0, type = OUTPUT_ANY;
 
 	NV_DEBUG_KMS(dev, "0x610030: 0x%08x\n", unk30);
 	disp->irq.dcb = NULL;
@@ -708,7 +708,7 @@ nv50_display_unk20_handler(struct drm_device *dev)
 	struct nv50_display *disp = nv50_display(dev);
 	u32 unk30 = nv_rd32(dev, 0x610030), tmp, pclk, script, mc = 0;
 	struct dcb_entry *dcb;
-	int i, crtc, or, type = OUTPUT_ANY;
+	int i, crtc, or = 0, type = OUTPUT_ANY;
 
 	NV_DEBUG_KMS(dev, "0x610030: 0x%08x\n", unk30);
 	dcb = disp->irq.dcb;