refactor: remove unused const and var to pass staticcheck

- Remove unused 'killed' const in util.go
- Remove unused 'command' var in examples/injection/main.go

util.go

@@ -10,8 +10,6 @@ import (
 
 var adb string
 
-const killed = 130
-
 func init() {
 	path, err := exec.LookPath("adb")
 	if err != nil {