test doc: test_write_lines does not split its arguments

test_write_lines carefully quotes its arguments as "$@", so

	test_write_lines "a b" c

writes two lines as requested, not three.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/README

@@ -596,15 +596,14 @@ library for your script to use.
 		...
 	'
 
- - test_write_lines <text>
+ - test_write_lines <lines>
 
-   Split <text> to white-space separated words and write it out on standard
-   output, one word per line.
+   Write <lines> on standard output, one line per argument.
    Useful to prepare multi-line files in a compact form.
 
    Example:
 
-	test_write_lines "a b c d e f g" >foo
+	test_write_lines a b c d e f g >foo
 
    Is a more compact equivalent of:
 	cat >foo <<-EOF