t5582: remove spurious 'cd "$D"' line

The variable D is never defined in test t5582, more severely the test
fails if D is defined by something outside the test suite, so remove
this spurious line.

Signed-off-by: Mickey Endito <mickey.endito.2323@protonmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t5582-fetch-negative-refspec.sh

@@ -105,7 +105,6 @@ test_expect_success "fetch with negative pattern refspec does not expand prefix"
 '
 
 test_expect_success "fetch with negative refspec avoids duplicate conflict" '
-	cd "$D" &&
 	(
 		cd one &&
 		git branch dups/a &&