Already upstream

--- a/src/api/sockets.c
+++ b/src/api/sockets.c
@@ -223,7 +223,7 @@
   /** error happened for this socket, set by event_callback(), tested by select */
   u16_t errevent;
   /** last error that occurred on this socket (in fact, all our errnos fit into an u8_t) */
-  u8_t err;
+  int err;
   /** counter of how many threads are waiting for this socket using select */
   SELWAIT_T select_waiting;
 };
@@ -309,7 +309,7 @@
 
 #define sock_set_errno(sk, e) do { \
   const int sockerr = (e); \
-  sk->err = (u8_t)sockerr; \
+  sk->err = (int)sockerr; \
   set_errno(sockerr); \
 } while (0)
 
@@ -319,8 +319,8 @@
 static void lwip_getsockopt_callback(void *arg);
 static void lwip_setsockopt_callback(void *arg);
 #endif
-static u8_t lwip_getsockopt_impl(int s, int level, int optname, void *optval, socklen_t *optlen);
-static u8_t lwip_setsockopt_impl(int s, int level, int optname, const void *optval, socklen_t optlen);
+static int lwip_getsockopt_impl(int s, int level, int optname, void *optval, socklen_t *optlen);
+static int lwip_setsockopt_impl(int s, int level, int optname, const void *optval, socklen_t optlen);
 
 #if LWIP_IPV4 && LWIP_IPV6
 static void
@@ -1804,7 +1804,7 @@
 int
 lwip_getsockopt(int s, int level, int optname, void *optval, socklen_t *optlen)
 {
-  u8_t err;
+  int err;
   struct lwip_sock *sock = get_socket(s);
 #if !LWIP_TCPIP_CORE_LOCKING
   LWIP_SETGETSOCKOPT_DATA_VAR_DECLARE(data);
@@ -1899,10 +1899,10 @@
 /** lwip_getsockopt_impl: the actual implementation of getsockopt:
  * same argument as lwip_getsockopt, either called directly or through callback
  */
-static u8_t
+static int
 lwip_getsockopt_impl(int s, int level, int optname, void *optval, socklen_t *optlen)
 {
-  u8_t err = 0;
+  int err = 0;
   struct lwip_sock *sock = tryget_socket(s);
   if (!sock) {
     return EBADF;
@@ -2210,7 +2210,7 @@
 int
 lwip_setsockopt(int s, int level, int optname, const void *optval, socklen_t optlen)
 {
-  u8_t err = 0;
+  int err = 0;
   struct lwip_sock *sock = get_socket(s);
 #if !LWIP_TCPIP_CORE_LOCKING
   LWIP_SETGETSOCKOPT_DATA_VAR_DECLARE(data);
@@ -2300,10 +2300,10 @@
 /** lwip_setsockopt_impl: the actual implementation of setsockopt:
  * same argument as lwip_setsockopt, either called directly or through callback
  */
-static u8_t
+static int
 lwip_setsockopt_impl(int s, int level, int optname, const void *optval, socklen_t optlen)
 {
-  u8_t err = 0;
+  int err = 0;
   struct lwip_sock *sock = tryget_socket(s);
   if (!sock) {
     return EBADF;
