btrfs: factor out devs_max setting in __btrfs_alloc_chunk

Merge the repeated code before the if-else block.
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/volumes.c

@@ -4956,6 +4956,8 @@ static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
 	sub_stripes = btrfs_raid_array[index].sub_stripes;
 	dev_stripes = btrfs_raid_array[index].dev_stripes;
 	devs_max = btrfs_raid_array[index].devs_max;
+	if (!devs_max)
+		devs_max = BTRFS_MAX_DEVS(info);
 	devs_min = btrfs_raid_array[index].devs_min;
 	devs_increment = btrfs_raid_array[index].devs_increment;
 	ncopies = btrfs_raid_array[index].ncopies;
@@ -4964,8 +4966,6 @@ static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
 	if (type & BTRFS_BLOCK_GROUP_DATA) {
 		max_stripe_size = SZ_1G;
 		max_chunk_size = BTRFS_MAX_DATA_CHUNK_SIZE;
-		if (!devs_max)
-			devs_max = BTRFS_MAX_DEVS(info);
 	} else if (type & BTRFS_BLOCK_GROUP_METADATA) {
 		/* for larger filesystems, use larger metadata chunks */
 		if (fs_devices->total_rw_bytes > 50ULL * SZ_1G)
@@ -4973,13 +4973,9 @@ static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
 		else
 			max_stripe_size = SZ_256M;
 		max_chunk_size = max_stripe_size;
-		if (!devs_max)
-			devs_max = BTRFS_MAX_DEVS(info);
 	} else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
 		max_stripe_size = SZ_32M;
 		max_chunk_size = 2 * max_stripe_size;
-		if (!devs_max)
-			devs_max = BTRFS_MAX_DEVS_SYS_CHUNK;
 	} else {
 		btrfs_err(info, "invalid chunk type 0x%llx requested",
 		       type);