Tweak intro comments to some MI test files.

Tweak intro comments to some MI test files.

A while ago I noticed there's some blind copy/pasting going on some test
intro comments.  This fixes some instances, in the MI testsuite.

Tested on x86_64 Fedora 17.

testsuite/
2013-02-12  Pedro Alves  <palves@redhat.com>

	* gdb.mi/mi-basics.exp: Tweak intro comment.
	* gdb.mi/mi-break.exp: Tweak intro comment.
	* gdb.mi/mi-console.exp: Tweak intro comment.
	* gdb.mi/mi-file.exp: Tweak intro comment.
	* gdb.mi/mi-read-memory.exp: Tweak intro comment.
	* gdb.mi/mi-return.exp: Tweak intro comment.
	* gdb.mi/mi-stepi.exp: Tweak intro comment.
	* gdb.mi/mi-until.exp: Tweak intro comment.
	* gdb.mi/mi-watch.exp: Tweak intro comment.