git-p4: fix small bug in locked test scripts

Test script t9816-git-p4-locked.sh test #4 tests for
adding a file that is locked by Perforce automatically.
This is currently not supported by git-p4 and so is
expected to fail.

However, a small typo meant it always failed, even with
a fixed git-p4. Fix the typo to resolve this.

Signed-off-by: Luke Diamand <luke@diamand.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t9816-git-p4-locked.sh

@@ -41,7 +41,7 @@ test_expect_failure 'add with lock not taken' '
 	(
 		cd "$git" &&
 		echo line1 >>add-lock-not-taken &&
-		git add file2 &&
+		git add add-lock-not-taken &&
 		git commit -m "add add-lock-not-taken" &&
 		git config git-p4.skipSubmitEdit true &&
 		git p4 submit --verbose