Remove unused return value

src/android.c

@@ -92,7 +92,7 @@ protect_socket(int fd)
     return ret;
 }
 
-int
+void
 send_traffic_stat(uint64_t tx, uint64_t rx)
 {
     int sock;
@@ -129,8 +129,6 @@ send_traffic_stat(uint64_t tx, uint64_t rx)
         return -1;
     }
 
-    char ret = 0;
-
     if (recv(sock, &ret, 1, 0) == -1) {
         ERROR("[android] recv");
         close(sock);
@@ -138,5 +136,4 @@ send_traffic_stat(uint64_t tx, uint64_t rx)
     }
 
     close(sock);
-    return ret;
 }

src/common.h

@@ -47,7 +47,7 @@ void free_udprelay(void);
 
 #ifdef __ANDROID__
 int protect_socket(int fd);
-int send_traffic_stat(uint64_t tx, uint64_t rx);
+void send_traffic_stat(uint64_t tx, uint64_t rx);
 #endif
 
 #define STAGE_ERROR     -1  /* Error detected                   */