staging/lustre/osc: don't activate deactivated obd_import

In ptlrpc_activate_import(), obd_import->imp_deactive should
be checked if it is deactivated, otherwise it will trigger an
LBUG in ptlrpc_invalidate_import():

  ptlrpc_invalidate_import() ASSERTION(imp->imp_invalid) failed
Signed-off-by: Hongchao Zhang <hongchao.zhang@intel.com>
Reviewed-on: http://review.whamcloud.com/8747
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-4386Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Fan Yong <fan.yong@intel.com>
Signed-off-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/lustre/lustre/ptlrpc/import.c

@@ -381,6 +381,11 @@ void ptlrpc_activate_import(struct obd_import *imp)
 	struct obd_device *obd = imp->imp_obd;
 
 	spin_lock(&imp->imp_lock);
+	if (imp->imp_deactive != 0) {
+		spin_unlock(&imp->imp_lock);
+		return;
+	}
+
 	imp->imp_invalid = 0;
 	spin_unlock(&imp->imp_lock);
 	obd_import_event(obd, imp, IMP_EVENT_ACTIVE);