drm/i915/fbc: Rewrite the FBC tiling check a bit

Write the tiling check in a nicer form. No functional
changes due to Y-tile scanout being a gen9+ feature.
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210702204603.596-2-ville.syrjala@linux.intel.com

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

@@ -675,11 +675,9 @@ static bool tiling_is_valid(struct drm_i915_private *dev_priv,
 {
 	switch (modifier) {
 	case DRM_FORMAT_MOD_LINEAR:
-		if (DISPLAY_VER(dev_priv) >= 9)
-			return true;
-		return false;
-	case I915_FORMAT_MOD_X_TILED:
 	case I915_FORMAT_MOD_Y_TILED:
+		return DISPLAY_VER(dev_priv) >= 9;
+	case I915_FORMAT_MOD_X_TILED:
 		return true;
 	default:
 		return false;