cf-net connect now exits with 1 in case of error

```
$ sudo /var/cfengine/bin/cf-net -H 192.168.123.456 connect
Failed to connect to '192.168.123.456'
$ echo $?
1
$ sudo /var/cfengine/bin/cf-net -H 127.0.0.1 connect
Connected & authenticated successfully to '127.0.0.1'
$ echo $?
0
```

Ticket: CFE-4414
Changelog: Title
Signed-off-by: Lars Erik Wik <lars.erik.wik@northern.tech>

Author: larsewi

cf-net/cf-net.c

@@ -472,7 +472,9 @@ static int CFNetRun(CFNetOptions *opts, char **args, char *hostnames)
     int ret = 0;
     char *hostname = strtok(hosts, ",");
     while (hostname != NULL){
-        CFNetCommandSwitch(opts, hostname, args, cmd);
+        if (CFNetCommandSwitch(opts, hostname, args, cmd) != 0) {
+            ret = -1;
+        }
         hostname = strtok(NULL, ",");
     }
     free(hosts);
@@ -636,8 +638,7 @@ static int CFNetConnect(const char *hostname, const char *use_protocol_version,
         Log(LOG_LEVEL_ERR, "No hostname specified");
         return -1;
     }
-    CFNetConnectSingle(hostname, use_protocol_version, true);
-    return 0;
+    return CFNetConnectSingle(hostname, use_protocol_version, true);
 }
 
 static void CFNetDisconnect(AgentConnection *conn)