util: Fix compilation of envlist.c for MinGW

MinGW has no strtok_r, so we need a declaration in sysemu/os-win32.h.
We must also fix the include statements in util/envlist.c to include
that file.

We currently don't need an implementation of strtok_r because the
code is compiled but not linked for MinGW.
Signed-off-by: NStefan Weil <sw@weilnetz.de>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

include/sysemu/os-win32.h

@@ -73,6 +73,8 @@ struct tm *gmtime_r(const time_t *timep, struct tm *result);
 #undef localtime_r
 struct tm *localtime_r(const time_t *timep, struct tm *result);
 
+char *strtok_r(char *str, const char *delim, char **saveptr);
+
 static inline void os_setup_signal_handling(void) {}
 static inline void os_daemonize(void) {}
 static inline void os_setup_post(void) {}

util/envlist.c

-#include <assert.h>
-#include <errno.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-
+#include "qemu-common.h"
 #include "qemu/queue.h"
 #include "qemu/envlist.h"