t: local VAR="VAL" (quote positional parameters)

Future-proof test scripts that do

	local VAR=VAL

without quoting VAL (which is OK in POSIX but broken in some shells)
that is a positional parameter, e.g. $4.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/lib-parallel-checkout.sh

@@ -20,7 +20,7 @@ test_checkout_workers () {
 		BUG "too few arguments to test_checkout_workers"
 	fi &&
 
-	local expected_workers=$1 &&
+	local expected_workers="$1" &&
 	shift &&
 
 	local trace_file=trace-test-checkout-workers &&