HID: hid-logitech-hidpp: add NULL check on devm_kmemdup() return value

Check return value from call to devm_kmemdup() in order to prevent a NULL
pointer dereference.

Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>