[PATCH] ipw2200: Reassociate even if set the same essid.

This patch traps the case when the essid is being set to its
current value. If the essid is being set again and we are already
associated, chances are some other parameters have also been altered.
I think it is safer to do the re-association for this case.

Signed-off-by: Bill Moss <bmoss@clemson.edu>
Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>