gettimeofday: fix name space pollution

For systems without its own gettimeofday() implementation, we still must
not provide one outside our namespace.

Reported by: Bill Segall

src/misc.c

@@ -424,7 +424,7 @@ _libssh2_debug(LIBSSH2_SESSION * session, int context, const char *format, ...)
         }
     }
 
-    gettimeofday(&now, NULL);
+    _libssh2_gettimeofday(&now, NULL);
     if(!firstsec) {
         firstsec = now.tv_sec;
     }
@@ -563,16 +563,15 @@ void _libssh2_list_insert(struct list_node *after, /* insert before this */
 
 #endif
 
-
-
-#if defined(LIBSSH2_WIN32) && !defined(__MINGW32__)
+/* this define is defined in misc.h for the correct platforms */
+#ifdef LIBSSH2_GETTIMEOFDAY_WIN32
 /*
  * gettimeofday
  * Implementation according to:
  * The Open Group Base Specifications Issue 6
  * IEEE Std 1003.1, 2004 Edition
  */
-  
+
 /*
  *  THIS SOFTWARE IS NOT COPYRIGHTED
  *
@@ -591,9 +590,7 @@ void _libssh2_list_insert(struct list_node *after, /* insert before this */
 /* Offset between 1/1/1601 and 1/1/1970 in 100 nanosec units */
 #define _W32_FT_OFFSET (116444736000000000)
 
-
-int __cdecl gettimeofday(struct timeval *tp,
-                         void *tzp)
+int __cdecl _libssh2_gettimeofday(struct timeval *tp, void *tzp)
  {
   union {
     unsigned __int64 ns100; /*time since 1 Jan 1601 in 100ns units */