common/lock.c: Fixed an error dealing with unistd.h not being Windows' standard.

git-svn-id: https://svn.code.sf.net/p/rathena/svn/branches/stable@1361 54d463be-8e91-2dee-dedb-b68131a5f0ec

src/common/lock.c

@@ -2,7 +2,13 @@
 #include <stdio.h>
 #include <errno.h>
 #include <string.h>
+#ifndef WIN32
 #include <unistd.h>
+#else
+#include <windows.h>
+#define F_OK   0x0
+#define R_OK   0x4
+#endif
 #include "lock.h"
 #include "showmsg.h"
 #define exists(filename) (!access(filename, F_OK))