rivafb & small 16 bit mode problem

I have already send this once before Xmas but it probably got lost, so I'm sending it again:

There is a problem with 16 bit mode with rivafb. Colors are sometimes broken (specialy under Midnight Commander). This small patch fixes it. I've been using it for last months and it works without any problems.

Pawel 'Goldi' Goleniowski

@@ -300,8 +300,8 @@
 
 static inline void convert_bgcolor_16(u32 *col)
 {
-	*col = ((*col & 0x00007C00) << 9)
-             | ((*col & 0x000003E0) << 6)
+	*col = ((*col & 0x0000F800) << 8)
+             | ((*col & 0x000007E0) << 5)
              | ((*col & 0x0000001F) << 3)
              |          0xFF000000;
 }