rebase: fix "rebase --continue" breakage

The --skip case was handled properly when rebasing without --merge,
but the --continue case was not.

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

git-rebase.sh

@@ -170,7 +170,11 @@ do
 			finish_rb_merge
 			exit
 		fi
-		git am --resolved --3way --resolvemsg="$RESOLVEMSG"
+		head_name=$(cat .dotest/head-name) &&
+		onto=$(cat .dotest/onto) &&
+		orig_head=$(cat .dotest/orig-head) &&
+		git am --resolved --3way --resolvemsg="$RESOLVEMSG" &&
+		move_to_original_branch
 		exit
 		;;
 	--skip)