t3005: remove unused variable

Since the beginning of the script, $new_line variable was never used.
Remove it.

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

t/t3005-ls-files-relative.sh

@@ -7,8 +7,6 @@ This test runs git ls-files with various relative path arguments.
 
 . ./test-lib.sh
 
-new_line='
-'
 sq=\'
 
 test_expect_success 'prepare' '