drm/radeon: Make IH ring overflow debugging output more useful

Use the same format for all ring indices, and fix the calculation of the
post-overflow RPTR.

Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/radeon/r600.c b/drivers/gpu/drm/radeon/r600.c
index 5514f1b..81f3236 100644
--- a/drivers/gpu/drm/radeon/r600.c
+++ b/drivers/gpu/drm/radeon/r600.c
@@ -3797,8 +3797,8 @@
 		 * from the last not overwritten vector (wptr + 16). Hopefully
 		 * this should allow us to catchup.
 		 */
-		dev_warn(rdev->dev, "IH ring buffer overflow (0x%08X, %d, %d)\n",
-			wptr, rdev->ih.rptr, (wptr + 16) + rdev->ih.ptr_mask);
+		dev_warn(rdev->dev, "IH ring buffer overflow (0x%08X, 0x%08X, 0x%08X)\n",
+			 wptr, rdev->ih.rptr, (wptr + 16) & rdev->ih.ptr_mask);
 		rdev->ih.rptr = (wptr + 16) & rdev->ih.ptr_mask;
 		tmp = RREG32(IH_RB_CNTL);
 		tmp |= IH_WPTR_OVERFLOW_CLEAR;