ipc: fix hangs in debug mode
ipc: fix hangs in debug mode

exec waits for readDone channel, but it is not closed in debug mode.
Close readDone in debug mode.

zoulasc/syzkaller,dotweiba/syzkaller,zoulasc/syzkaller,hyz0906/syzkaller,dotweiba/syzkaller,xairy/syzkaller,google/syzkaller,hyz0906/syzkaller,xairy/syzkaller,google/syzkaller,hyz0906/syzkaller,hyz0906/syzkaller,dotweiba/syzkaller,xairy/syzkaller,dotweiba/syzkaller,xairy/syzkaller,zoulasc/syzkaller,google/syzkaller,xairy/syzkaller,hyz0906/syzkaller,xairy/syzkaller,google/syzkaller,google/syzkaller,google/syzkaller,zoulasc/syzkaller,xairy/syzkaller,google/syzkaller