Translated Java to Golang.

Original solution by Vinod

```
func findCircleNum(M [][]int) int {
var visited = make([]int, len(M))
count := 0
for i := 0; i < len(M); i ++ {
if visited[i] == 0 {
dfs(M, visited, i)
count++
}
}
return count
}
func dfs(M [][]int, visited []int, i int) {
for j := 0; j < len(M); j ++ {
if (M[i][j] == 1 && visited[j] == 0) {
visited[j] = 1
dfs(M, visited, j)
}
}
}
```