scripts/config: allow colons in option strings for sed

Sed broke on some strings as it used colon as a separator.
I made it more robust by using \001, which is legit POSIX AFAIK.

E.g. ./config --set-str CONFIG_USBNET_DEVADDR "de:ad:be:ef:00:01"
failed with: sed: -e expression #1, char 55: unknown option to `s'
Signed-off-by: Jeremie Francois (on alpha) <jeremie.francois@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

scripts/config

@@ -7,6 +7,9 @@ myname=${0##*/}
 # If no prefix forced, use the default CONFIG_
 CONFIG_="${CONFIG_-CONFIG_}"
 
+# We use an uncommon delimiter for sed substitutions
+SED_DELIM=$(echo -en "\001")
+
 usage() {
 	cat >&2 <<EOL
 Manipulate options in a .config file from the command line.
@@ -83,7 +86,7 @@ txt_subst() {
 	local infile="$3"
 	local tmpfile="$infile.swp"
 
-	sed -e "s:$before:$after:" "$infile" >"$tmpfile"
+	sed -e "s$SED_DELIM$before$SED_DELIM$after$SED_DELIM" "$infile" >"$tmpfile"
 	# replace original file with the edited one
 	mv "$tmpfile" "$infile"
 }