Fix bad declaration

Not sure how it's called but i guess it would have resulted in crashes or memory corruption
(cherry picked from commit d626fdc4)

modules/misc/notify/xosd.c

@@ -108,7 +108,7 @@ static int Open( vlc_object_t *p_this )
 {
     intf_thread_t *p_intf = (intf_thread_t *)p_this;
     xosd *p_osd;
-    char *psz_font, psz_colour;
+    char *psz_font, *psz_colour;
 
     /* Allocate instance and initialize some members */
     p_intf->p_sys = (intf_sys_t *)malloc( sizeof( intf_sys_t ) );