[Bugfix Rockbox#2] initialize the volume names for the sim

and fix red for the devices that don't have ext drives

Change-Id: I66b8ea1e1b22a42cee2957a504756e7f785bd0ae

uisimulator/common/sim_tasks.c

@@ -30,7 +30,10 @@
 #include "usb.h"
 #include "mv.h"
 #include "ata_idle_notify.h"
-#include "pathfuncs.h"
+#ifdef HAVE_MULTIVOLUME
+#include "pathfuncs.h" /* for init_volume_names */
+#endif
+
 #ifdef WIN32
 #include <windows.h>
 #endif
@@ -134,7 +137,9 @@ void sim_thread(void)
 
 void sim_tasks_init(void)
 {
+#ifdef HAVE_MULTIVOLUME
     init_volume_names();
+#endif
     queue_init(&sim_queue, false);
 
     create_thread(sim_thread, sim_thread_stack, sizeof(sim_thread_stack), 0,