Revert "contrib: subtree: adjust test to change in fmt-merge-msg"

This reverts commit 508fd8e.

In 6e6029a (fmt-merge-msg: allow merge destination to be omitted again)
we get back the behavior where merges against 'master', by default, do
not include "into 'master'" at the end of the merge message. This test
fix is no longer needed.

Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: nasamuffin

contrib/subtree/t/t7900-subtree.sh

@@ -196,8 +196,7 @@ test_expect_success 'merge new subproj history into sub dir/ with --prefix' '
 		cd "$subtree_test_count" &&
 		git fetch ./"sub proj" master &&
 		git subtree merge --prefix="sub dir" FETCH_HEAD &&
-		check_equal "$(last_commit_message)" \
-			"Merge commit '\''$(git rev-parse FETCH_HEAD)'\'' into master"
+		check_equal "$(last_commit_message)" "Merge commit '\''$(git rev-parse FETCH_HEAD)'\''"
 	)
 '
 
@@ -274,8 +273,7 @@ test_expect_success 'merge new subproj history into subdir/ with a slash appende
 		cd "$test_count" &&
 		git fetch ./subproj master &&
 		git subtree merge --prefix=subdir/ FETCH_HEAD &&
-		check_equal "$(last_commit_message)" \
-			"Merge commit '\''$(git rev-parse FETCH_HEAD)'\'' into master"
+		check_equal "$(last_commit_message)" "Merge commit '\''$(git rev-parse FETCH_HEAD)'\''"
 	)
 '