qerror/block: introduce QERR_BLOCK_JOB_NOT_ACTIVE

The DeviceNotActive text is not a particularly good match, add
a separate text while keeping the same class.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
diff --git a/qerror.h b/qerror.h
index d0a76a4..485c773 100644
--- a/qerror.h
+++ b/qerror.h
@@ -48,6 +48,9 @@
 #define QERR_BASE_NOT_FOUND \
     ERROR_CLASS_GENERIC_ERROR, "Base '%s' not found"
 
+#define QERR_BLOCK_JOB_NOT_ACTIVE \
+    ERROR_CLASS_DEVICE_NOT_ACTIVE, "No active block job on device '%s'"
+
 #define QERR_BLOCK_FORMAT_FEATURE_NOT_SUPPORTED \
     ERROR_CLASS_GENERIC_ERROR, "Block format '%s' used by device '%s' does not support feature '%s'"