apply: plug a leak in apply_data

apply: plug a leak in apply_data

We have an execution path in apply_data that leaks the local struct
image.  Plug it.

This leak can be triggered with:

    $ echo foo >file
    $ git add file && git commit -m file
    $ echo bar >file
    $ git diff file >diff
    $ sed s/foo/frotz/ <diff >baddiff
    $ git apply --cached <baddiff

Fixing this leak allows us to mark as leak-free the following tests:

    + t2016-checkout-patch.sh
    + t4103-apply-binary.sh
    + t4104-apply-boundary.sh
    + t4113-apply-ending.sh
    + t4117-apply-reject.sh
    + t4123-apply-shrink.sh
    + t4252-am-options.sh
    + t4258-am-quoted-cr.sh

Mark them with "TEST_PASSES_SANITIZE_LEAK=true" to notice and fix
promply any new leak that may be introduced and triggered by them in the
future.

Signed-off-by: Rubén Justo <rjusto@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>