drm/i915: Fix enum pipe vs. enum transcoder for the PCH transcoder

Use enum pipe for PCH transcoders also in the FIFO underrun code.

Fixes the following new sparse warnings:
intel_fifo_underrun.c:340:49: warning: mixing different enum types
intel_fifo_underrun.c:340:49:     int enum pipe  versus
intel_fifo_underrun.c:340:49:     int enum transcoder
intel_fifo_underrun.c:344:49: warning: mixing different enum types
intel_fifo_underrun.c:344:49:     int enum pipe  versus
intel_fifo_underrun.c:344:49:     int enum transcoder
intel_fifo_underrun.c:397:57: warning: mixing different enum types
intel_fifo_underrun.c:397:57:     int enum pipe  versus
intel_fifo_underrun.c:397:57:     int enum transcoder
intel_fifo_underrun.c:398:17: warning: mixing different enum types
intel_fifo_underrun.c:398:17:     int enum pipe  versus
intel_fifo_underrun.c:398:17:     int enum transcoder

Cc: Matthias Kaehlcke <mka@chromium.org>
Fixes: a21960339c8c ("drm/i915: Consistently use enum pipe for PCH transcoders")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170901143123.7590-3-ville.syrjala@linux.intel.com
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
diff --git a/drivers/gpu/drm/i915/i915_trace.h b/drivers/gpu/drm/i915/i915_trace.h
index b24a83d..6fd5c57 100644
--- a/drivers/gpu/drm/i915/i915_trace.h
+++ b/drivers/gpu/drm/i915/i915_trace.h
@@ -38,7 +38,7 @@ TRACE_EVENT(intel_cpu_fifo_underrun,
 );
 
 TRACE_EVENT(intel_pch_fifo_underrun,
-	    TP_PROTO(struct drm_i915_private *dev_priv, enum transcoder pch_transcoder),
+	    TP_PROTO(struct drm_i915_private *dev_priv, enum pipe pch_transcoder),
 	    TP_ARGS(dev_priv, pch_transcoder),
 
 	    TP_STRUCT__entry(
@@ -48,7 +48,7 @@ TRACE_EVENT(intel_pch_fifo_underrun,
 			     ),
 
 	    TP_fast_assign(
-			   enum pipe pipe = (enum pipe)pch_transcoder;
+			   enum pipe pipe = pch_transcoder;
 			   __entry->pipe = pipe;
 			   __entry->frame = dev_priv->drm.driver->get_vblank_counter(&dev_priv->drm, pipe);
 			   __entry->scanline = intel_get_crtc_scanline(intel_get_crtc_for_pipe(dev_priv, pipe));