fix: connecting to a non-existing port on switch returns error

[samuelemusiani]

I have found a bug where if you try to connect to a port on the switch that does not exists the connection will hang. To reproduce the bug:

1. Open a terminal and start a switch: vde_switch /tmp/sw1
2. Open another terminal and try to connect to any port >= 32: vdens '/tmp/sw1[33]'

This patch should fix the bug. After this if you try to connect to a non-existing port the
error message vdeplug: No such file or directory is returned.

[berdav]

I see that there it is some confusion on coding style (e.g. curly brackets and else placement).

LFTM.

[berdav]

For instance, this else branch modification is not necessary.

[samuelemusiani]

I should do something like this?

}
else {

So this apply to the other if statements too? So from this:

if () {
} else {
    remove_fd(fd);
}

to this

if () {
}
else {
    remove_fd(fd);
}

[samuelemusiani]

Also I've just notice that the else if statement on line 252 is in the wrong format, right?

[berdav]

Yes, I think it would be better to refactor the project in future with a consistent coding style (for instance the Linux one).

It is not relevant for this pr.

[samuelemusiani]

Ok, makes sense. Code formatters are made for this :)