tests: allocate memory in a coherent fashion
tests: allocate memory in a coherent fashion

Do not free memory allocated with C functions (like calloc) using g_free;
although this is possible with default Glib allocator this is not safe.
Also use consistent allocation functions. All other spice-server code
does not use Glib allocations so for coherence do not use them for
watches.

Signed-off-by: Frediano Ziglio <55d48b080b2e443e395cde84d2c83b135a4ff48e@redhat.com>
Acked-by: Victor Toso <39b7599ff73bbf5db531748ba5250f21fa7120ff@redhat.com>

SPICE/spice,fgouget/spice,fgouget/spice,fgouget/spice,SPICE/spice,fgouget/spice,SPICE/spice