tests: fixed "ovn-nbctl - daemon retry connection"

"kill pid" does not wait for process to be terminated.
Wait for ovsdb-server termination before restarting it.

Signed-off-by: Xavier Simonart <[email protected]>
Signed-off-by: Dumitru Ceara <[email protected]>
(cherry picked from commit 8b65cbd)

Author: simonartxavier

Diff for: tests/ovn-nbctl.at

@@ -2695,7 +2695,9 @@ dnl ---------------------------------------------------------------------
 
 AT_SETUP([ovn-nbctl - daemon retry connection])
 OVN_NBCTL_TEST_START daemon
-AT_CHECK([kill `cat ovsdb-server.pid`])
+pid=$(cat ovsdb-server.pid)
+AT_CHECK([kill $pid])
+OVS_WAIT_WHILE([kill -0 $pid 2>/dev/null])
 AT_CHECK([ovsdb-server --detach --no-chdir --pidfile --log-file --remote=punix:$OVS_RUNDIR/ovnnb_db.sock ovn-nb.db], [0], [], [stderr])
 AT_CHECK([ovn-nbctl show], [0], [ignore])
 OVN_NBCTL_TEST_STOP "/terminating with signal 15/d"