[x86 setup] The current display page is returned in %bh, not %bl

The current display page is an 8-bit number, even though struct
screen_info gives it a 16-bit number.  The number is returned in %bh,
so it needs to be >> 8 before storing.

Special thanks to Jeff Chua for detailed bug reporting.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

arch/i386/boot/video.c

@@ -61,7 +61,7 @@ static void store_video_mode(void)
 
 	/* Not all BIOSes are clean with respect to the top bit */
 	boot_params.screen_info.orig_video_mode = ax & 0x7f;
-	boot_params.screen_info.orig_video_page = page;
+	boot_params.screen_info.orig_video_page = page >> 8;
 }
 
 /*