ide: Improve error messages

Use error_report(), because it points to the error location.

Reword "tried to assign twice" messages to make it clear that we're
complaining about the unit property.

Report invalid unit property instead of failing silently.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

hw/ide/qdev.c

@@ -18,7 +18,7 @@
  */
 #include <hw/hw.h>
 #include "dma.h"
-
+#include "qemu-error.h"
 #include <hw/ide/internal.h>
 
 /* --------------------------------- */
@@ -40,7 +40,7 @@ static int ide_qdev_init(DeviceState *qdev, DeviceInfo *base)
     IDEBus *bus = DO_UPCAST(IDEBus, qbus, qdev->parent_bus);
 
     if (!dev->conf.bs) {
-        fprintf(stderr, "%s: no drive specified\n", qdev->info->name);
+        error_report("No drive specified");
         goto err;
     }
     if (dev->unit == -1) {
@@ -49,19 +49,20 @@ static int ide_qdev_init(DeviceState *qdev, DeviceInfo *base)
     switch (dev->unit) {
     case 0:
         if (bus->master) {
-            fprintf(stderr, "ide: tried to assign master twice\n");
+            error_report("IDE unit %d is in use", dev->unit);
             goto err;
         }
         bus->master = dev;
         break;
     case 1:
         if (bus->slave) {
-            fprintf(stderr, "ide: tried to assign slave twice\n");
+            error_report("IDE unit %d is in use", dev->unit);
             goto err;
         }
         bus->slave = dev;
         break;
     default:
+        error_report("Invalid IDE unit %d", dev->unit);
         goto err;
     }
     return info->init(dev);