regulator: max8997: Test pdata by NULL checking instead of IS_ERR_OR_NULL

pdata is either a valid pointer or NULL, use NULL checking rather than
IS_ERR_OR_NULL macro.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
1 file changed