dvbinfo: OSX Maverick build fix.

Fix error: unknown type name 'ssize_t'; did you mean 'size_t' when building on
OSX Maverick.
Signed-off-by: Jean-Paul Saman <jpsaman@videolan.org>

examples/dvbinfo/buffer.c

@@ -32,6 +32,7 @@
 #   include <stdint.h>
 #endif
 
+#include <sys/types.h>
 #include <assert.h>
 
 typedef int64_t mtime_t;