staging: wilc1000: remove WILC_MemoryFree

It's no longer needed, so remove the empty wrapper function.

Cc: Johnny Kim <johnny.kim@atmel.com>
Cc: Rachel Kim <rachel.kim@atmel.com>
Cc: Dean Lee <dean.lee@atmel.com>
Cc: Chris Park <chris.park@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>