qemu-img: Fix check's leak/corruption fix report

There are two problems with qemu-img check's report on how many leaks
and/or corruptions have been fixed:

(1) ImageCheck.has_leaks_fixed and ImageCheck.has_corruptions_fixed are
only true when ImageCheck.leaks or ImageCheck.corruptions (respectively)
are non-zero.  qcow2's check implementation will set the latter to zero
after it has fixed leaks and corruptions, though, so leaks-fixed and
corruptions-fixed are actually never reported after successful repairs.
We should always report them when they are non-zero, just like all the
other fields of ImageCheck.

(2) After something has been fixed and we run the check a second time,
leaks_fixed and corruptions_fixed are taken from the first run; but
has_leaks_fixed and has_corruptions_fixed are not.  The second run
actually cannot fix anything, so with (1) fixed, has_leaks_fixed and
has_corruptions_fixed will always be false here.  (With (1) unfixed,
they will at least be false on successful runs, because then the number
of leaks and corruptions found in the second run should be 0.)
We should save has_leaks_fixed and has_corruptions_fixed just like we
save leaks_fixed and corruptions_fixed.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200324172757.1173824-2-mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>