manager: properly cleanup on ctrl+C
manager: properly cleanup on ctrl+C

Don't leave temporal files behind.

dotweiba/syzkaller,sploving/syzkaller,dotweiba/syzkaller,lorenzo-stoakes/syzkaller,xairy/syzkaller,sploving/syzkaller,lorenzo-stoakes/syzkaller,zoulasc/syzkaller,xairy/syzkaller,zoulasc/syzkaller,hyz0906/syzkaller,xairy/syzkaller,xairy/syzkaller,xairy/syzkaller,dotweiba/syzkaller,sploving/syzkaller,google/syzkaller,google/syzkaller,google/syzkaller,google/syzkaller,google/syzkaller,google/syzkaller,google/syzkaller,hyz0906/syzkaller,dotweiba/syzkaller,sploving/syzkaller,hyz0906/syzkaller,lorenzo-stoakes/syzkaller,hyz0906/syzkaller,xairy/syzkaller,xairy/syzkaller,hyz0906/syzkaller,zoulasc/syzkaller,zoulasc/syzkaller