Fix sanitizer errors in posix socket (#2331)

core/shared/platform/common/posix/posix_socket.c

@@ -275,6 +275,9 @@ os_socket_recv_from(bh_socket_t socket, void *buf, unsigned int len, int flags,
             return -1;
         }
     }
+    else {
+        memset(src_addr, 0, sizeof(*src_addr));
+    }
 
     return ret;
 }