xf86-video-fbturbo: fix build

srcpkgs/xf86-video-fbturbo/patches/gcc8.patch

@@ -0,0 +1,20 @@
+--- src/fbdev.c.orig
++++ src/fbdev.c
+@@ -1037,7 +1037,7 @@
+ 	fPtr->CloseScreen = pScreen->CloseScreen;
+ 	pScreen->CloseScreen = FBDevCloseScreen;
+ 
+-#if XV
++#ifdef XV
+ 	fPtr->SunxiVideo_private = NULL;
+ 	if (xf86ReturnOptValBool(fPtr->Options, OPTION_XV_OVERLAY, TRUE) &&
+ 	fPtr->sunxi_disp_private) {
+@@ -1126,7 +1126,7 @@
+ 	    fPtr->SunxiDispHardwareCursor_private = NULL;
+ 	}
+ 
+-#if XV
++#ifdef XV
+ 	if (fPtr->SunxiVideo_private) {
+ 	    SunxiVideo_Close(pScreen);
+ 	    free(fPtr->SunxiVideo_private);