psxdevctl is supposed to return the value in errno. Before, it was
returning -1 and setting errno. Changed the tests to reflect these
changes. Added code from RRADE's posix_devctl.c.
Closes#4506
The FACE Technical Standard, Edition 3.0 and later require the definition
of the subcommand SOCKCLOSE in <devctl.h>.
Reference: https://www.opengroup.org/facecloses#3856.
