tests (rebase): spell out the --force-rebase option

In quite a few test cases, we were sloppy and used the abbreviation
`--force`, but we really should be precise in what we want to test.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t3415-rebase-autosquash.sh

@@ -277,7 +277,7 @@ test_expect_success 'autosquash with empty custom instructionFormat' '
 	(
 		set_cat_todo_editor &&
 		test_must_fail git -c rebase.instructionFormat= \
-			rebase --autosquash  --force -i HEAD^ >actual &&
+			rebase --autosquash  --force-rebase -i HEAD^ >actual &&
 		git log -1 --format="pick %h %s" >expect &&
 		test_cmp expect actual
 	)

t/t3430-rebase-merges.sh

@@ -271,7 +271,7 @@ test_expect_success 'root commits' '
 	EOF
 	test_config sequence.editor \""$PWD"/replace-editor.sh\" &&
 	test_tick &&
-	git rebase -i --force --root -r &&
+	git rebase -i --force-rebase --root -r &&
 	test "Parsnip" = "$(git show -s --format=%an HEAD^)" &&
 	test $(git rev-parse second-root^0) != $(git rev-parse HEAD^) &&
 	test $(git rev-parse second-root:second-root.t) = \
@@ -364,7 +364,7 @@ test_expect_success 'octopus merges' '
 	test_cmp_rev HEAD $before &&
 
 	test_tick &&
-	git rebase -i --force -r HEAD^^ &&
+	git rebase -i --force-rebase -r HEAD^^ &&
 	test "Hank" = "$(git show -s --format=%an HEAD)" &&
 	test "$before" != $(git rev-parse HEAD) &&
 	test_cmp_graph HEAD^^.. <<-\EOF