sisfb: fix color component length for pseudocolor modes

sisfb incorrectly sets the length of the color fields to 6 bits
for PSEUDOCOLOR modes, even though 8 bits are always used per pixel.
Fix this by setting the length to 8.
Signed-off-by: Michal Januszewski <spock@gentoo.org>
Cc: Thomas Winischhofer <thomas@winischhofer.net>
Acked-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/video/sis/sis_main.c

@@ -1129,7 +1129,7 @@ sisfb_bpp_to_var(struct sis_video_info *ivideo, struct fb_var_screeninfo *var)
 	switch(var->bits_per_pixel) {
 	case 8:
 		var->red.offset = var->green.offset = var->blue.offset = 0;
-		var->red.length = var->green.length = var->blue.length = 6;
+		var->red.length = var->green.length = var->blue.length = 8;
 		break;
 	case 16:
 		var->red.offset = 11;