tests: better check for array in sync

Update check for raid array being in sync - getting somewhat complex.
It's another way to fight with problems in:
https://bugzilla.redhat.com/show_bug.cgi?id=1210637

test/lib/check.sh

@@ -212,7 +212,7 @@ in_sync() {
 
 	b=( $(echo ${a[$idx]} | sed s:/:' ':) )
 
-	if [ ${b[0]} != ${b[1]} ]; then
+	if [ ${a[$(($idx + 1))]} != "idle" -o ${b[0]} -eq 0 -o ${b[0]} != ${b[1]} ]; then
 		echo "$lvm_name ($type$snap) is not in-sync"
 		return 1
 	fi