staging: wilc1000: fix to use correct index to free scanned info in clear_shadow_scan()

Fixes to use correct index to free the allocated memory for ies
information. The check was done using 'last_scanned_cnt' index and its
not correct, so use the correct index ('i') to check for before freeing
the allocated memory.

Signed-off-by: Ajay Singh <ajay.kathat@microchip.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>