[Libguestfs] plug leaks in febootstrap

[Jim Meyering]

Jim Meyering wrote:
> I ran coverity against febootstrap's head and it spotted four leaks.
> This fixes them.  The first patch plugs three.
> The second attempts to make the add_link function do what I'm
> guessing it was intended to do.  As is, it was a no-op.
...
> Subject: [PATCH 1/2] helper: plug three small leaks
>
> * helper/ext2initrd.c (read_module_deps): Don't leak filename.
> (ext2_make_initrd): Don't leak "outfile".
> * helper/utils.c (load_file): Don't leak a file pointer.
...
> Subject: [PATCH 2/2] helper: fix no-op add_link function
>
> * helper/ext2cpio.c (add_link): Don't leak just-allocated buffer.
> Instead, link it into links_head list.

FYI, after a go-ahead from Rich, I've pushed these two.