sys/targets: fix shadowed flag variable
sys/targets: fix shadowed flag variable

env CGO_ENABLED=1 GOMAXPROCS=1 GOGC=50 gometalinter.v2 ./...
sys/targets/targets.go:428::warning: declaration of "flag" shadows declaration at sys/targets/targets.go:423 (vetshadow)

xairy/syzkaller,google/syzkaller,xairy/syzkaller,google/syzkaller,google/syzkaller,google/syzkaller,xairy/syzkaller,xairy/syzkaller,google/syzkaller,xairy/syzkaller,google/syzkaller,xairy/syzkaller,google/syzkaller,xairy/syzkaller