check: really improve test list randomization

coreutils provides the shuf(1) utility that randomizes the order of a
list and seeds its random number generator with /dev/urandom.  It's a
bit speedier than awk, so use it if available.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Eryu Guan <guaneryu@gmail.com>
Signed-off-by: Eryu Guan <guaneryu@gmail.com>

check

@@ -243,7 +243,11 @@ _prepare_test_list()
 
 	# sort the list of tests into numeric order
 	if $randomize; then
-		sorter="awk -v seed=$RANDOM -f randomize.awk"
+		if type shuf >& /dev/null; then
+			sorter="shuf"
+		else
+			sorter="awk -v seed=$RANDOM -f randomize.awk"
+		fi
 	else
 		sorter="cat"
 	fi