msvc: define ftello()

It is just called differently in MSVC's headers.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

compat/msvc.h

@@ -18,6 +18,8 @@
 
 #undef ERROR
 
+#define ftello _ftelli64
+
 typedef int sigset_t;
 /* open for reading, writing, or both (not in fcntl.h) */
 #define O_ACCMODE     (_O_RDONLY | _O_WRONLY | _O_RDWR)