gdb.mi/mi-console.c, gdb.mi/mi-stack.c: Remove local emacs variables defining change...

gdb.mi/mi-console.c, gdb.mi/mi-stack.c: Remove local emacs variables defining change-log-default-name.

These references to ChangeLog-mi are stale.
testsuite/gdb.mi/ChangeLog-mi doesn't exist anymore, since:

...
commit 2dd627049d915a78ba15b65ab718d54958d115bf
Author: Andrew Cagney <cagney@redhat.com>
Date:   Sat Jun 23 21:47:09 2001 +0000

    Rename gdb.mi/ChangeLog-mi to gdb.mi/ChangeLog.  Update everything.
...
commit 48efe7049b1c286c702621e2f3e89e4584df2bd2
Author: Andrew Cagney <cagney@redhat.com>
Date:   Mon Jan 12 15:16:44 2004 +0000

    Eliminate the old mi/tui specific ChangeLog files as in ...

    Added Files:
        mi/ChangeLog-1999-2003 testsuite/gdb.mi/ChangeLog-1999-2003
        tui/ChangeLog-1998-2003
    Removed Files:
        mi/ChangeLog testsuite/gdb.mi/ChangeLog tui/ChangeLog

Tested with 'make check RUNTESTFLAGS="--directory=gdb.mi"' on x86_64 Fedora 17.

gdb/testsuite/
2013-10-29  Pedro Alves  <palves@redhat.com>

	* gdb.mi/mi-console.c, gdb.mi/mi-stack.c: Remove local emacs
	variable setting change-log-default-name to ChangeLog-mi.