iwlwifi: fix debug messages during scanning

direct_mask will be set when we are not associated and requesting a
direct scan. The second debug print will be confusing as priv->essid
is not set at that time and it will thus print "<hidden>" while it is
known to which AP a direct scan is requested - as previous debug message
also indicates.

Now make all debugging consistent.

Signed-off-by: Bill Moss <bmoss@clemson.edu>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>