glib/goption.c: Replace precondition with assertion
glib/goption.c: Replace precondition with assertion

A static analysis run noted that we weren't freeing the cmdline in the
error path here.  We can just make this an assertion instead; I just
checked the kernel code, and it just usees a seq_printf() here which
will NUL terminate.

endlessm/glib,endlessm/glib,endlessm/glib,endlessm/glib,endlessm/glib