qemuxml2xmltest: Convert hugepages related tests to _CAPS_LATEST

qemuxml2xmltest: Convert hugepages related tests to _CAPS_LATEST

Currently, we have maybe a dozen tests for hugepages related stuff in
qemuxml2xmltest. In all cases DO_TEST() is used, which means we have to
enumerate all capabilities needed (though, it's usually just
QEMU_CAPS_OBJECT_MEMORY_RAM and QEMU_CAPS_OBJECT_MEMORY_FILE,
exceptionally QEMU_CAPS_DEVICE_PC_DIMM too).

Instead of deleting the caps flags one-by-one, just switch the
tests to use DO_CAPS_LATEST().

Since some of our expected output files are just a symlink to their
respective input files, these are changed too. But from QEMU's
POV nothing changes as no .args file is changed.

Oh, and I'm also adding a 'hugepages-memaccess3' test case, which
was missing, surprisingly.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>