fdtoverlay: Switch from using alloca to malloc

alloca entails a complicated header situation when using other platforms, where
some split it out in alloca.h while others include it as a standard part of
stdlib.h.

The cons don't seem to outweigh the pros, so switch it to malloc.

Signed-off-by: Kyle Evans <kevans@FreeBSD.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
1 file changed