Move temporary bcol/bcol2 off of Graphics

Looks like I had missed yet another two temporary variables that were
actually globals on the Graphics class. Glad I caught these ones.

desktop_version/src/Graphics.cpp

@@ -104,8 +104,6 @@ void Graphics::init()
 
     // initialize everything else to zero
     backBuffer = NULL;
-    bcol = 0;
-    bcol2 = 0;
     ct = colourTransform();
     foot_rect = SDL_Rect();
     foregrounddrawn = false;
@@ -1966,6 +1964,9 @@ void Graphics::drawbackground( int t )
         }
         break;
     case 2:
+    {
+        int bcol, bcol2;
+
             //Lab
             switch(rcol)
             {
@@ -2112,6 +2113,7 @@ void Graphics::drawbackground( int t )
             FillRect(backBuffer,backboxrect, bcol2);
         }
         break;
+    }
     case 3: //Warp zone (horizontal)
         FillRect(backBuffer, 0x000000);
         BlitSurfaceStandard(towerbuffer, NULL, towerbuffer_lerp, NULL);

desktop_version/src/Graphics.h

@@ -200,7 +200,7 @@ public:
 
 	colourTransform ct;
 
-	int bcol, bcol2, rcol;
+	int rcol;