HID: amd_sfh: Fix potential NULL pointer dereference

The cl_data field of a privdata must be allocated and updated before
using in amd_sfh_hid_client_init() function.

Hence handling NULL pointer cl_data accordingly.

Fixes: d46ef750

 ("HID: amd_sfh: Fix potential NULL pointer dereference")
Signed-off-by: Basavaraj Natikar <Basavaraj.Natikar@amd.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>