Fix build with CS_ENABLE_STDIO=0

Closes https://github.com/cesanta/mongoose/pull/945

CL: Fix build with CS_ENABLE_STDIO=0

PUBLISHED_FROM=7d15f17fc42241facdba5b1004b5b7f3dda599dc

src/common/cs_dbg.c

@@ -31,13 +31,12 @@ enum cs_log_level cs_log_threshold WEAK =
     LL_ERROR;
 #endif
 
+#if CS_ENABLE_STDIO
 static char *s_filter_pattern = NULL;
 static size_t s_filter_pattern_len;
 
 void cs_log_set_filter(const char *pattern) WEAK;
 
-#if CS_ENABLE_STDIO
-
 FILE *cs_log_file WEAK = NULL;
 
 #if CS_LOG_ENABLE_TS_DIFF

src/common/cs_dbg.h

@@ -117,6 +117,8 @@ void cs_log_set_file(FILE *file);
  */
 void cs_log_printf(const char *fmt, ...) PRINTF_LIKE(1, 2);
 
+#if CS_ENABLE_STDIO
+
 /*
  * Format and print message `x` with the given level `l`. Example:
  *
@@ -130,6 +132,12 @@ void cs_log_printf(const char *fmt, ...) PRINTF_LIKE(1, 2);
     if (cs_log_print_prefix(l, __func__, __FILE__)) cs_log_printf x; \
   } while (0)
 
+#else
+
+#define LOG(l, x) ((void) l)
+
+#endif
+
 #ifndef CS_NDEBUG
 
 /*

src/common/platforms/lwip/mg_lwip_net_if.c

@@ -501,6 +501,8 @@ static void mg_lwip_tcp_write_tcpip(void *arg) {
     return;
   }
   ctx->ret = len;
+  (void) unsent;
+  (void) unacked;
 }
 
 int mg_lwip_if_tcp_send(struct mg_connection *nc, const void *buf, size_t len) {