have test suite continue even if ndbcluster fails to start if --force flag is set

mysql-test/include/have_ndb.inc

+--exec test x$NDB_STATUS_OK = x1
 -- require r/have_ndb.require
 disable_query_log;
 show variables like "have_ndbcluster";

mysql-test/mysql-test-run.sh

@@ -693,6 +693,8 @@ export NDB_MGM
 export NDB_BACKUP_DIR
 export NDB_TOOLS_OUTPUT
 export PURIFYOPTIONS
+NDB_STATUS_OK=1
+export NDB_STATUS_OK
 
 MYSQL_TEST_ARGS="--no-defaults --socket=$MASTER_MYSOCK --database=$DB \
  --user=$DBUSER --password=$DBPASSWD --silent -v --skip-safemalloc \
@@ -1055,7 +1057,15 @@ start_ndbcluster()
     else
       NDBCLUSTER_EXTRA_OPTS="--small"
     fi
-    ./ndb/ndbcluster $NDBCLUSTER_OPTS $NDBCLUSTER_EXTRA_OPTS --initial || exit 1
+    ./ndb/ndbcluster $NDBCLUSTER_OPTS $NDBCLUSTER_EXTRA_OPTS --initial || NDB_STATUS_OK=0
+    if [ x$NDB_STATUS_OK != x1 ] ; then
+      if [ x$FORCE != x1 ] ; then
+        exit 1
+      fi
+      USE_NDBCLUSTER=
+      return
+    fi
+
     NDB_CONNECTSTRING="host=localhost:$NDBCLUSTER_PORT"
   else
     NDB_CONNECTSTRING="$USE_RUNNING_NDBCLUSTER"