change variable i to $i in an expression of ifstart() for consistency

with the rest of the file.  no functional change.
feedback from sthen@, ok krw@

src/etc/netstart

@@ -1,6 +1,6 @@
 #!/bin/sh -
 #
-#	$OpenBSD: netstart,v 1.125 2009/07/10 19:08:08 jdixon Exp $
+#	$OpenBSD: netstart,v 1.126 2009/09/17 08:22:22 simon Exp $
 
 # Strip comments (and leading/trailing whitespace if IFS is set)
 # from a file and spew to stdout
@@ -66,7 +66,7 @@ ifstart() {
 			# Make sure and get any remaining args in ext2,
 			# like the read below
 			i=1
-			while [ i -lt 6 -a -n "$1" ]; do shift; let i=i+1; done
+			while [ $i -lt 6 -a -n "$1" ]; do shift; let i=i+1; done
 			ext2="$@"
 		else
 			# Read the next line or exit the while loop.