Optimize and simplify the selection of the latest library version in

reorder_libs().
From Klemens Nanni with input from rpe.
ok rpe, zhuk

src/etc/rc

@@ -1,4 +1,4 @@
-#	$OpenBSD: rc,v 1.507 2017/07/04 19:02:11 rpe Exp $
+#	$OpenBSD: rc,v 1.508 2017/07/17 12:02:53 tb Exp $
 
 # System startup script run by init on autoboot or after single-user.
 # Output and error are redirected to console by init, and the console is the
@@ -158,7 +158,7 @@ make_keys() {
 
 # Re-link libraries, placing the objects in a random order.
 reorder_libs() {
-	local _dkdev _l _liba _libas _mp _tmpdir _remount=false _error=false
+	local _dkdev _liba _libas _mp _tmpdir _remount=false _error=false
 
 	[[ $library_aslr == NO ]] && return
 
@@ -171,13 +171,10 @@ reorder_libs() {
 	echo -n 'reordering libraries:'
 
 	# Only choose the latest version of the libraries.
-	for _liba in /usr/lib/libc.so.*.a /usr/lib/libcrypto.so.*.a; do
-		_liba=$(ls ${_liba%%.[0-9]*}*.a | sort -V | tail -1)
-		for _l in $_libas; do
-			[[ $_l == $_liba ]] && continue 2
-		done
-		_libas="$_libas $_liba"
+	for _liba in /usr/lib/lib{c,crypto}; do
+		_libas="$_libas $(ls $_liba.so.+([0-9.]).a | sort -V | tail -1)"
 	done
+	_libas=${_libas# }
 
 	# Remount read-write, if /usr/lib is on a read-only ffs filesystem.
 	if [[ $_mp == *' type ffs '*'read-only'* ]]; then