staging/ft1000: Return -ENOMEM if kmalloc fails at ft1000_probe

If the kmalloc fails return -ENOMEM , returning 0 is not the proper
way if any function fails

Signed-off-by: Devendra Naga <devendra.aaru@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>