spicevmc: Change creation of RedCharDeviceSpiceVmc
spicevmc: Change creation of RedCharDeviceSpiceVmc

Instead of having channel and device object create one the other
create the objects at the beginning and then join them.

This make explicit the code that links the two objects and separate
the objects creation from the linking.

Also remove some boilerplate code.

Signed-off-by: Frediano Ziglio <55d48b080b2e443e395cde84d2c83b135a4ff48e@redhat.com>
Signed-off-by: Jonathon Jongsma <c7254805a17bd5c41e24c3a278fcbf3afcdfb0fa@redhat.com>
Acked-by: Jonathon Jongsma <c7254805a17bd5c41e24c3a278fcbf3afcdfb0fa@redhat.com>
Acked-by: Frediano Ziglio <55d48b080b2e443e395cde84d2c83b135a4ff48e@redhat.com>

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