Use socklen_t on Android and other POSIX-compliant system

Fixes #2977

Signed-off-by: okhowang(王沛文) <okhowang@tencent.com>
diff --git a/library/net_sockets.c b/library/net_sockets.c
index 3f96cab..54c2b47 100644
--- a/library/net_sockets.c
+++ b/library/net_sockets.c
@@ -318,7 +318,7 @@
 
 #if defined(__socklen_t_defined) || defined(_SOCKLEN_T) ||  \
     defined(_SOCKLEN_T_DECLARED) || defined(__DEFINED_socklen_t) || \
-    defined(socklen_t)
+    defined(socklen_t) || (defined(_POSIX_VERSION) && _POSIX_VERSION >= 200112L)
     socklen_t n = (socklen_t) sizeof( client_addr );
     socklen_t type_len = (socklen_t) sizeof( type );
 #else