fix: wrong use of fallthrough in marshalling paramWrapperType

[paulip1792]

	switch t.Kind() {
	case reflect.Ptr:
		// unwrap pointer
		v = v.Elem()
		t = t.Elem()
		fallthrough

	case reflect.Struct:
		// if its a struct, walk its fields and recurse.
...

Fallthrough will execute the action in next case regardless of the condition.
case reflect.Struct will be executed even if the pointee of a pointer is not a Struct.

package main

import (
	"fmt"
)

func main() {
	eval := func() int {
		fmt.Println("eval")
		return 2
	}
	switch {
	case 1 == 1:
		fmt.Println("1 == 1")
		fallthrough
	case eval() == 1:
		fmt.Println("2 == 1")
	}
}

Output:

1 == 1
2 == 1

Go Playground

[iand]

LGTM

[frrist]

Great catch @paulip1792.