tests: check for clvmd process entry

Instead of checking just for pid file - rather check
for process  - since there could be slight race, the
pid file is gone, but process still exists.

test/shell/pvmove-restart.sh

@@ -69,7 +69,7 @@ if test -e LOCAL_CLVMD ; then
 	kill $(< LOCAL_CLVMD)
 	for i in $(seq 1 100) ; do
 		test $i -eq 100 && die "Shutdown of clvmd is too slow."
-		test -e "$CLVMD_PIDFILE" || break
+		pgrep clvmd || break
 		sleep .1
 	done # wait for the pid removal
 	aux prepare_clvmd