drm/i915: Use pipe_name() instead of the pipe number

Yet other direct usages of the pipe number instead of pipe_name().
We've been tracking them lately but managed to miss these last ones.

v2: Catch them all! (Ville)

Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> (v1)
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_dsi.c b/drivers/gpu/drm/i915/intel_dsi.c
index 9a2fdd2..d257b09 100644
--- a/drivers/gpu/drm/i915/intel_dsi.c
+++ b/drivers/gpu/drm/i915/intel_dsi.c
@@ -350,7 +350,7 @@
 	unsigned int bpp = intel_crtc->config.pipe_bpp;
 	u32 val, tmp;
 
-	DRM_DEBUG_KMS("pipe %d\n", pipe);
+	DRM_DEBUG_KMS("pipe %c\n", pipe_name(pipe));
 
 	/* Update the DSI PLL */
 	vlv_enable_dsi_pll(intel_encoder);