initialize errev fd
initialize errev fd

it can not be 0, 0 is an useful fd, this will cause weird
closing of ptmx fd.

Signed-off-by: Gao feng <7f710758e13fe1707f3aa2e93d3a8f5444b6a90e@gmail.com>

hyperhq/hyperstart,laijs/hyperstart,bergwolf/hyperstart,bergwolf/hyperstart,gnawux/hyperstart,gao-feng/hyperstart,wcwxyz/hyperstart,laijs/hyperstart,MarioCarrilloA/hyperstart,MarioCarrilloA/hyperstart,gao-feng/hyperstart,gnawux/hyperstart,MarioCarrilloA/hyperstart,hyperhq/hyperstart,gnawux/hyperstart,wcwxyz/hyperstart