gcc: fix !BR2_LARGEFILE builds

see http://lists.busybox.net/pipermail/buildroot/2013-August/076278.html



Signed-off-by: Francois Perrad <francois.perrad@gadz.org>
Tested-by: Thomas De Schampheleire <thomas.de.schampheleire@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>