Staging: wilc1000: wilc_msgqueue: Use kmemdup instead of kmalloc and memcpy

Replace kmalloc and memcpy with kmemdup.
Problem found using coccicheck

Signed-off-by: Shraddha Barke <shraddha.6596@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>