vendor/getinfo: Iterate through vendors in lexicographic order

find(1) works in readdir() order, which isn't guaranteed to be sorted.
If the current vendor is not an exact match for any subdirectory in
vendor/, and is somehow a derivative of more than one of them, we should
at least produce a deterministic answer.

Closes: #924662
Signed-off-by: Simon McVittie <smcv@collabora.com>

vendor/getinfo

@@ -6,7 +6,7 @@ BASEDIR="$(readlink -f "$(dirname $0)")"
 getcurrent() {
 	# search for an exact match to use the correct sources.list example
 	cd $BASEDIR
-	DISTROS="$(find . -mindepth 1 -maxdepth 1 -type d | cut -d'/' -f 2)"
+	DISTROS="$(find . -mindepth 1 -maxdepth 1 -type d | cut -d'/' -f 2 | LC_ALL=C sort)"
 	for DISTRO in $DISTROS; do
 		if dpkg-vendor --is $DISTRO; then
 			echo $DISTRO