lis3lv02d: Omit IRQF_ONESHOT if no threaded handler is provided

lis3lv02d: Omit IRQF_ONESHOT if no threaded handler is provided

The lis3lv02d started triggering a WARN in the IRQ code because it
passes IRQF_ONESHOT to request_threaded_irq() even when thread_fn is
NULL, which is an invalid combination.

So set the flag only if thread_fn is non-NULL.

Cc: Eric Piel <eric.piel@tremplin-utc.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://patch.msgid.link/20260326180436.14968-2-ardb@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>