[fix] Draw effect target

kernel/graphics/layer.cpp

@@ -1,5 +1,5 @@
 #include <graphics/layer.h>
-#include <graphics/rect.h>
+#include <graphics/draw.h>
 #include <graphics/context.h>
 #include <memory/heap.h>
 #include <memory/pmm.h>
@@ -273,7 +273,9 @@ void layer_compositor_task(void) {
 
         // Clear back buffer
         EFI_GRAPHICS_OUTPUT_BLT_PIXEL black = {0, 0, 0, 0};
-        gfx_fill_rect(g_back_buffer, hr, vr, 0, 0, hr, vr, black);
+        draw_set_target(g_back_buffer, hr, vr);
+        draw_rect(0, 0, hr, vr, black);
+        draw_set_default_target();
 
         // Composite layers from lowest z to highest
         layer_t* cur = g_layer_list;