extlinux: pull in sys/sysmacros.h for major/minor/makedev

These functions are defined in sys/sysmacros.h, so add the include to
main.c.  This is already handled correctly in mountinfo.c.  Otherwise
we get build failures like:

main.o: In function 'find_device_sysfs':
extlinux/main.c:1131: undefined reference to 'minor'

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Gene Cumm <gene.cumm@gmail.com>
1 file changed