Rename socket_loopback_server to _socket_loopback_server.

The master branch of this project gets included in ancient emulator
branches, that still have socket_loopback_server in libcutils. Prepend
an underscore in the local static implementation to avoid collision.

Test: treehugger
Change-Id: I458f3aeccee0cfeadc8226d64887ff5d0820c1d7
diff --git a/shared/OpenglCodecCommon/TcpStream.cpp b/shared/OpenglCodecCommon/TcpStream.cpp
index 9454f4a..2090ae0 100644
--- a/shared/OpenglCodecCommon/TcpStream.cpp
+++ b/shared/OpenglCodecCommon/TcpStream.cpp
@@ -28,7 +28,7 @@
 #include <ws2tcpip.h>
 #endif
 
-static int socket_loopback_server(int port, int type)
+static int _socket_loopback_server(int port, int type)
 {
     struct sockaddr_in addr;
 
@@ -81,7 +81,7 @@
 
 int TcpStream::listen(unsigned short port)
 {
-    m_sock = socket_loopback_server(port, SOCK_STREAM);
+    m_sock = _socket_loopback_server(port, SOCK_STREAM);
     if (!valid()) return int(ERR_INVALID_SOCKET);
 
     return 0;