* src/common.h: do not override lseek on Cygwin, only on mingw32. Cygwin

    provides its own 64-bit offset lseek. 

src/common.h

@@ -50,10 +50,9 @@
 #      define PATH_MAX MAX_PATH
 #   endif
 
-#   define lseek64 _lseeki64
-
 /* several type definitions */
 #   if defined( __MINGW32__ )
+#       define lseek _lseeki64
 #       if !defined( _OFF_T_ )
 typedef long long _off_t;
 typedef _off_t off_t;