video: fbdev: stifb.c: use container_of to resolve stifb_info from fb_info

Use container_of instead of casting first structure member.
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

drivers/video/fbdev/stifb.c

@@ -918,7 +918,7 @@ static int
 stifb_setcolreg(u_int regno, u_int red, u_int green,
 	      u_int blue, u_int transp, struct fb_info *info)
 {
-	struct stifb_info *fb = (struct stifb_info *) info;
+	struct stifb_info *fb = container_of(info, struct stifb_info, info);
 	u32 color;
 
 	if (regno >= NR_PALETTE)
@@ -978,7 +978,7 @@ stifb_setcolreg(u_int regno, u_int red, u_int green,
 static int
 stifb_blank(int blank_mode, struct fb_info *info)
 {
-	struct stifb_info *fb = (struct stifb_info *) info;
+	struct stifb_info *fb = container_of(info, struct stifb_info, info);
 	int enable = (blank_mode == 0) ? ENABLE : DISABLE;
 
 	switch (fb->id) {