style: remove extra const keyword from interfaces

Const variables in prototypes don't add much value, but make the code
larger and redundant. Remove these const keywords.
Note, this doesn't apply to pointers to const memory.

src/sock.c

@@ -69,7 +69,7 @@ static int _in_progress(int error)
 #endif
 }
 
-sock_t sock_connect(const char *const host, const unsigned short port)
+sock_t sock_connect(const char *host, unsigned short port)
 {
     sock_t sock;
     char service[6];
@@ -109,7 +109,7 @@ sock_t sock_connect(const char *const host, const unsigned short port)
     return sock;
 }
 
-int sock_set_keepalive(const sock_t sock, int timeout, int interval)
+int sock_set_keepalive(sock_t sock, int timeout, int interval)
 {
     int ret;
     int optval = (timeout && interval) ? 1 : 0;
@@ -154,7 +154,7 @@ int sock_set_keepalive(const sock_t sock, int timeout, int interval)
     return ret;
 }
 
-int sock_close(const sock_t sock)
+int sock_close(sock_t sock)
 {
 #ifdef _WIN32
     return closesocket(sock);
@@ -180,27 +180,27 @@ static int _sock_set_blocking_mode(sock_t sock, int blocking)
 #endif
 }
 
-int sock_set_blocking(const sock_t sock)
+int sock_set_blocking(sock_t sock)
 {
     return _sock_set_blocking_mode(sock, 1);
 }
 
-int sock_set_nonblocking(const sock_t sock)
+int sock_set_nonblocking(sock_t sock)
 {
     return _sock_set_blocking_mode(sock, 0);
 }
 
-int sock_read(const sock_t sock, void *const buff, const size_t len)
+int sock_read(sock_t sock, void *buff, size_t len)
 {
     return recv(sock, buff, len, 0);
 }
 
-int sock_write(const sock_t sock, const void *const buff, const size_t len)
+int sock_write(sock_t sock, const void *buff, size_t len)
 {
     return send(sock, buff, len, 0);
 }
 
-int sock_is_recoverable(const int error)
+int sock_is_recoverable(int error)
 {
 #ifdef _WIN32
     return (error == WSAEINTR || error == WSAEWOULDBLOCK ||
@@ -210,7 +210,7 @@ int sock_is_recoverable(const int error)
 #endif
 }
 
-int sock_connect_error(const sock_t sock)
+int sock_connect_error(sock_t sock)
 {
     struct sockaddr_storage ss;
     struct sockaddr *sa = (struct sockaddr *)&ss;