drm/i915/sdvo: Propagate errors from reading/writing control bus.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Eric Anholt <eric@anholt.net>
diff --git a/drivers/gpu/drm/i915/intel_sdvo_regs.h b/drivers/gpu/drm/i915/intel_sdvo_regs.h
index ba5cdf8..4988660 100644
--- a/drivers/gpu/drm/i915/intel_sdvo_regs.h
+++ b/drivers/gpu/drm/i915/intel_sdvo_regs.h
@@ -312,7 +312,7 @@
 # define SDVO_CLOCK_RATE_MULT_4X				(1 << 3)
 
 #define SDVO_CMD_GET_SUPPORTED_TV_FORMATS		0x27
-/** 5 bytes of bit flags for TV formats shared by all TV format functions */
+/** 6 bytes of bit flags for TV formats shared by all TV format functions */
 struct intel_sdvo_tv_format {
     unsigned int ntsc_m:1;
     unsigned int ntsc_j:1;