Kill references to netns in comment about how it conflicted with netipx so

it was ignored all this time.

usr.bin/kdump/mkioctls

@@ -18,11 +18,9 @@ LC_ALL=C; export LC_ALL
 
 # Build a list of headers that have ioctls in them.
 # XXX should we use an ANSI cpp?
-# XXX netipx conflicts with netns (leave out netns).
 ioctl_includes=`
 	cd $1
 	find -s * -name '*.h' -follow |
-		egrep -v '^(netns)/' |
 		xargs egrep -l \
 '^#[ 	]*define[ 	]+[A-Za-z_][A-Za-z0-9_]*[ 	]+_IO[^a-z0-9_]' |
 		awk '{printf("#include <%s>\\\\n", $1)}'