Fix miot-mbed errors and warning, part 3

PUBLISHED_FROM=2f6fb7ea5abdcd4ca9b06956172938ee3bc28459

mongoose.c

@@ -9485,7 +9485,7 @@ int mg_match_prefix(const char *pattern, int pattern_len, const char *str) {
   return mg_match_prefix_n(pstr, mg_mk_str(str));
 }
 
-MG_INTERNAL int mg_get_errno(void) {
+DO_NOT_WARN_UNUSED MG_INTERNAL int mg_get_errno(void) {
 #ifndef WINCE
   return errno;
 #else

mongoose.h

@@ -129,11 +129,13 @@
 #define NOINLINE __attribute__((noinline))
 #define WARN_UNUSED_RESULT __attribute__((warn_unused_result))
 #define NOINSTR __attribute__((no_instrument_function))
+#define DO_NOT_WARN_UNUSED __attribute__((unused))
 #else
 #define NORETURN
 #define NOINLINE
 #define WARN_UNUSED_RESULT
 #define NOINSTR
+#define DO_NOT_WARN_UNUSED
 #endif /* __GNUC__ */
 
 #ifndef ARRAY_SIZE
@@ -883,6 +885,10 @@ typedef struct stat cs_stat_t;
 #include <stdint.h>
 #include <string.h>
 #include <time.h>
+#include <sys/stat.h>
+#include <stdio.h>
+
+typedef struct stat cs_stat_t;
 
 #ifndef CS_ENABLE_STDIO
 #define CS_ENABLE_STDIO 1