kiosk-shell: Swap green with blue for the background-color

Fix a trivial typo, where the green channel was swapped with the blue
channel, resulting in rbg instead of rgb.

Signed-off-by: Marius Vlad <marius.vlad@collabora.com>

kiosk-shell/kiosk-shell.c

@@ -475,8 +475,8 @@ kiosk_shell_output_recreate_background(struct kiosk_shell_output *shoutput)
 						&bg_color, 0x00000000);
 
 	r = ((bg_color >> 16) & 0xff) / 255.0;
-	b = ((bg_color >> 8) & 0xff) / 255.0,
-	g = ((bg_color >> 0) & 0xff) / 255.0;
+	g = ((bg_color >> 8) & 0xff) / 255.0;
+	b = ((bg_color >> 0) & 0xff) / 255.0;
 
 	shoutput->background_view =
 			create_colored_surface(shoutput->shell->compositor,