regulator: max77802: fix a test in max77802_set_suspend_mode()

The original test triggers a static checker warning.  Javier Martinez
Canillas says that the "!" is a typo and should be removed.

Fixes: 2e0eaa1a ('regulator: max77802: Add set suspend mode for BUCKs and simplify code')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Tested-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: Mark Brown <broonie@kernel.org>