iwlagn: fix witespace damage

patch "iwlagn: check ready in iwlagn_bss_info_changed()" introduce
whitespace, fix it

please merge with the previous patch

Reported by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>