fix: staticcheck and deadcode findings repo-wide, modernize counting loops

cmd/gasm/main.go

@@ -1526,7 +1526,7 @@ func cmdVerifyCall(k *verify.Kernel, path, funcName, bufSpec, scalarSpec string,
 	fmt.Printf("  args before: %s\n", hexDump(args))
 
 	rc := 0
-	for i := 0; i < repeat; i++ {
+	for i := range repeat {
 		out, err := k.CallFunc(funcName, args)
 		if err != nil {
 			fmt.Printf("  call %d: FAIL — %v\n", i+1, err)
@@ -1575,7 +1575,7 @@ func hexDump(buf []byte) string {
 		n = max
 	}
 	var sb strings.Builder
-	for i := 0; i < n; i++ {
+	for i := range n {
 		if i > 0 {
 			sb.WriteByte(' ')
 		}