drm/i915: use DRM_ERROR() instead of drm_err()

Unify on current common usage to allow repurposing drm_err() later. Fix
newlines while at it.
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191002145405.27848-1-jani.nikula@intel.com

drivers/gpu/drm/i915/display/intel_display.c

@@ -12562,10 +12562,10 @@ pipe_config_infoframe_mismatch(struct drm_i915_private *dev_priv,
 		drm_dbg(DRM_UT_KMS, "found");
 		hdmi_infoframe_log(KERN_DEBUG, dev_priv->drm.dev, b);
 	} else {
-		drm_err("mismatch in %s infoframe", name);
-		drm_err("expected:");
+		DRM_ERROR("mismatch in %s infoframe\n", name);
+		DRM_ERROR("expected:\n");
 		hdmi_infoframe_log(KERN_ERR, dev_priv->drm.dev, a);
-		drm_err("found");
+		DRM_ERROR("found:\n");
 		hdmi_infoframe_log(KERN_ERR, dev_priv->drm.dev, b);
 	}
 }
@@ -12583,7 +12583,7 @@ pipe_config_mismatch(bool fastset, const char *name, const char *format, ...)
 	if (fastset)
 		drm_dbg(DRM_UT_KMS, "fastset mismatch in %s %pV", name, &vaf);
 	else
-		drm_err("mismatch in %s %pV", name, &vaf);
+		DRM_ERROR("mismatch in %s %pV\n", name, &vaf);
 
 	va_end(args);
 }