btrfs: fix devs_max constraints for raid1c3 and raid1c4

The value 0 for devs_max means to spread the allocated chunks over all
available devices, eg. stripe for RAID0 or RAID5. This got mistakenly
copied to the RAID1C3/4 profiles. The intention is to have exactly 3 and
4 copies respectively.

Fixes: 47e6f742 ("btrfs: add support for 3-copy replication (raid1c3)")
Fixes: 8d6fac00 ("btrfs: add support for 4-copy replication (raid1c4)")
Signed-off-by: NDavid Sterba <dsterba@suse.com>

fs/btrfs/volumes.c

@@ -61,7 +61,7 @@ const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
 	[BTRFS_RAID_RAID1C3] = {
 		.sub_stripes	= 1,
 		.dev_stripes	= 1,
-		.devs_max	= 0,
+		.devs_max	= 3,
 		.devs_min	= 3,
 		.tolerated_failures = 2,
 		.devs_increment	= 3,
@@ -73,7 +73,7 @@ const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
 	[BTRFS_RAID_RAID1C4] = {
 		.sub_stripes	= 1,
 		.dev_stripes	= 1,
-		.devs_max	= 0,
+		.devs_max	= 4,
 		.devs_min	= 4,
 		.tolerated_failures = 3,
 		.devs_increment	= 4,