fbdev: clean up exit patch of fb_set_var

Clean up exit patch of fb_set_var():

- consolidate all return values into a single local variable
- ensure that return values are valid error codes
- fix fb_set_var() returning success when fb_check_caps() failed
Signed-off-by: NAntonino Daplas <adaplas@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

drivers/video/fbmem.c

@@ -799,11 +799,11 @@ static int fb_check_caps(struct fb_info *info, struct fb_var_screeninfo *var,
 int
 fb_set_var(struct fb_info *info, struct fb_var_screeninfo *var)
 {
-	int err, flags = info->flags;
+	int flags = info->flags;
+	int ret = 0;
 
 	if (var->activate & FB_ACTIVATE_INV_MODE) {
 		struct fb_videomode mode1, mode2;
-		int ret = 0;
 
 		fb_var_to_videomode(&mode1, var);
 		fb_var_to_videomode(&mode2, &info->var);
@@ -821,7 +821,9 @@ fb_set_var(struct fb_info *info, struct fb_var_screeninfo *var)
 		if (!ret)
 		    fb_delete_videomode(&mode1, &info->modelist);
 
-		return ret;
+
+		ret = (ret) ? -EINVAL : 0;
+		goto done;
 	}
 
 	if ((var->activate & FB_ACTIVATE_FORCE) ||
@@ -830,20 +832,21 @@ fb_set_var(struct fb_info *info, struct fb_var_screeninfo *var)
 
 		if (!info->fbops->fb_check_var) {
 			*var = info->var;
-			return 0;
+			goto done;
 		}
 
-		if ((err = info->fbops->fb_check_var(var, info)))
-			return err;
+		ret = info->fbops->fb_check_var(var, info);
+
+		if (ret)
+			goto done;
 
 		if ((var->activate & FB_ACTIVATE_MASK) == FB_ACTIVATE_NOW) {
 			struct fb_videomode mode;
-			int err = 0;
 
 			if (info->fbops->fb_get_caps) {
-				err = fb_check_caps(info, var, activate);
+				ret = fb_check_caps(info, var, activate);
 
-				if (err)
+				if (ret)
 					goto done;
 			}
 
@@ -853,16 +856,14 @@ fb_set_var(struct fb_info *info, struct fb_var_screeninfo *var)
 				info->fbops->fb_set_par(info);
 
 			fb_pan_display(info, &info->var);
-
 			fb_set_cmap(&info->cmap, info);
-
 			fb_var_to_videomode(&mode, &info->var);
 
 			if (info->modelist.prev && info->modelist.next &&
 			    !list_empty(&info->modelist))
-				err = fb_add_videomode(&mode, &info->modelist);
+				ret = fb_add_videomode(&mode, &info->modelist);
 
-			if (!err && (flags & FBINFO_MISC_USEREVENT)) {
+			if (!ret && (flags & FBINFO_MISC_USEREVENT)) {
 				struct fb_event event;
 				int evnt = (activate & FB_ACTIVATE_ALL) ?
 					FB_EVENT_MODE_CHANGE_ALL :
@@ -876,7 +877,7 @@ fb_set_var(struct fb_info *info, struct fb_var_screeninfo *var)
 	}
 
  done:
-	return 0;
+	return ret;
 }
 
 int