btrfs: unfold transaction aborts at btrfs_create_new_inode()

Instead of having a common btrfs_abort_transaction() call for when either
btrfs_orphan_add() failed or when btrfs_add_link() failed, move the
btrfs_abort_transaction() to happen immediately after each one of those
calls, so that when analysing a stack trace with a transaction abort we
know which call failed.

Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: David Sterba <dsterba@suse.com>