syz-extract: don't fail if no flags to extract
syz-extract: don't fail if no flags to extract

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