Revert "reset: Make reset remove the sequencer state"

This reverts commit 95eb88d8ee, which
was a UI experiment that did not reflect how "git reset" actually gets
used.  The reversion also fixes a test, indicated in the patch.

Encouraged-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

branch.c

@@ -3,7 +3,6 @@
 #include "refs.h"
 #include "remote.h"
 #include "commit.h"
-#include "sequencer.h"
 
 struct tracking {
 	struct refspec spec;
@@ -247,5 +246,4 @@ void remove_branch_state(void)
 	unlink(git_path("MERGE_MSG"));
 	unlink(git_path("MERGE_MODE"));
 	unlink(git_path("SQUASH_MSG"));
-	remove_sequencer_state(0);
 }