QError: Add QERR_DEVICE_NOT_ACTIVE

New class for device not active errors.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
diff --git a/qerror.c b/qerror.c
index a12e7f7..0c0a510 100644
--- a/qerror.c
+++ b/qerror.c
@@ -44,6 +44,10 @@
         .error_fmt = QERR_DEVICE_NOT_FOUND,
         .desc      = "The %(device) device has not been found",
     },
+    {
+        .error_fmt = QERR_DEVICE_NOT_ACTIVE,
+        .desc      = "The %(device) device has not been activated by the guest",
+    },
     {}
 };