sysroot: Plug some leaks
sysroot: Plug some leaks

The deployments and booted deployment were never unreffed.

Also, remote (void) from the call to the unload function - it returns
nothing, so there is no need to fool the compiler.

Closes: #287
Approved by: cgwalters

gatispaeglis/ostree,GNOME/ostree,gatispaeglis/ostree,GNOME/ostree,gatispaeglis/ostree,gatispaeglis/ostree,gatispaeglis/ostree,GNOME/ostree,GNOME/ostree,gatispaeglis/ostree,GNOME/ostree