sh testsuite: sync ash-vars/ and hush-vars/

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/shell/ash_test/ash-vars/var4.tests b/shell/ash_test/ash-vars/var4.tests
new file mode 100755
index 0000000..07feaeb
--- /dev/null
+++ b/shell/ash_test/ash-vars/var4.tests
@@ -0,0 +1 @@
+X=usbdev1.2 X=${X#usbdev} B=${X%%.*} D=${X#*.}; echo bus/usb/$B/$D