Prefix C function by gopsutil_v3_

[PierreF]

Fix #1175

With this hopefully unique enough prefix, the C functions defined by gopsutil should not longer conflict with either version 2 of gopsutil or another CGO library

With this change, the following program works:

package main

import (
	"fmt"
	v2disk "github.com/shirou/gopsutil/disk"
	v2host "github.com/shirou/gopsutil/host"
	v3disk "github.com/shirou/gopsutil/v3/disk"
	v3host "github.com/shirou/gopsutil/v3/host"
)

func main() {
	fmt.Println(v3host.SensorsTemperatures())
	fmt.Println(v3disk.IOCounters())
	fmt.Println(v2host.SensorsTemperatures())
	fmt.Println(v2disk.IOCounters())
}

[shirou]

Thank you so much. But we will terminate version 2 on end of this month (PR: #1174). After that, the name will be no longer conflicts. Users who cannot migrate to v3 will be using v2 and v3 at the same time, which may cause conflicts. However, we want to encourage people to migrate to v3.

[PierreF]

In my use case, this will means I can't upgrade to v3 yet, because I indirectly depend on v2.
I'll try to push the v3 on the dependency that use v2.

[mx-psi]

I think as @PierreF mentioned on their issue this would be useful to avoid conflicts with any other package, not just v2

Note that this conflict is not necessary limited to version 2 and version 3 of gopsutil. If any other package define the same C function (e.g. version 2 of gopsutil and github.com/lufia/iostat, which both define readdrivestat) a conflict also occur :(

[shirou]

with any other package, not just v2

Understand, agreed. Then, I will merge this PR. But after #1174 merged, please forgive us to remove "v3" from the name, like "gopsutil_readdrivestat".

Thank you for your kind contributions!