btrfs: remove duplicate system chunk array max size overflow check

btrfs: remove duplicate system chunk array max size overflow check

We check it twice, once in validate_sys_chunk_array() and then again in
its caller, btrfs_validate_super(), right after it calls
validate_sys_chunk_array(). So remove the duplicated check from
btrfs_validate_super().

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>