btrfs-progs: tests: enumerate RWX in convert tests

Generating all valid combinations takes too much time.

Signed-off-by: David Sterba <dsterba@suse.com>

tests/convert-tests.sh

@@ -57,7 +57,10 @@ generate_dataset() {
 			;;
 
 		perm)
-			for modes in $(seq 1 7777); do
+			for modes in 777 775 755 750 700 666 664 644 640 600 444 440 400 000		\
+				1777 1775 1755 1750 1700 1666 1664 1644 1640 1600 1444 1440 1400 1000	\
+				2777 2775 2755 2750 2700 2666 2664 2644 2640 2600 2444 2440 2400 2000	\
+				4777 4775 4755 4750 4700 4666 4664 4644 4640 4600 4444 4440 4400 4000; do
 				if [[ "$modes" == *9* ]] || [[ "$modes" == *8* ]]
 				then
 					continue;