Fix greedy debug grep

From Bugzilla #527:

if you have a kernel with say a '-g' in it, then KERNEL_DIR will include the
'-g' in it, CFLAGS will include the '-g' in it, and then the grep will think you
have -g in your CFLAGS

for example, if you use the grsec or gentoo patchset:
$ uname -r
2.6.19.1-grsec
$ uname -r
2.6.19-gentoo-r2

then your CFLAGS will look like:
-O2 -Wall -Wunused -I"/lib/modules/2.6.19.1-grsec/build"/include -Iinclude/
-DIPTABLES_VERSION=\"1.3.7\"

and the greedy check grep will incorrectly flag this:
egrep -e '-g|-pg|IPTC_DEBUG'
1 file changed