Specify that we need TCP and not UDP connection

Relevant man pages say that with our previous
code libc might return either. Glibc returns tcp but
bionic returns udp. So specify it explicitly

uart/uart_posix.c

@@ -78,7 +78,7 @@ serial_port uart_open(const char* pcPortName)
   if (sp == 0) return INVALID_SERIAL_PORT;
 
   if (memcmp(pcPortName, "tcp:", 4) == 0) {
-    struct addrinfo *addr, *rp;
+    struct addrinfo *addr = NULL, *rp;
     char *addrstr = strdup(pcPortName + 4);
     if (addrstr == NULL) {
       printf("Error: strdup\n");
@@ -96,7 +96,13 @@ if (colon) {
     } else
       portstr = "7901";
 
-    int s = getaddrinfo(addrstr, portstr, NULL, &addr);
+    struct addrinfo info;
+
+    memset (&info, 0, sizeof(info));
+
+    info.ai_socktype = SOCK_STREAM;
+
+    int s = getaddrinfo(addrstr, portstr, &info, &addr);
     if (s != 0) {
       printf("Error: getaddrinfo: %s\n", gai_strerror(s));
       return INVALID_SERIAL_PORT;