fix preprocessor conditions

Author: weltling

win32/time.h

@@ -28,15 +28,13 @@ struct itimerval {
 	struct timeval it_value;	/* current value */
 };
 
-#ifndef timespec
-#if _MSC_VER < 1900
+#if !defined(timespec) && _MSC_VER < 1900
 struct timespec
 {
 	time_t   tv_sec;   /* seconds */
 	long     tv_nsec;  /* nanoseconds */
 };
 #endif
-#endif
 
 #define ITIMER_REAL    0		/*generates sigalrm */
 #define ITIMER_VIRTUAL 1		/*generates sigvtalrm */