regulator: aat2870: Fix the logic of checking if no id is matched in aat2870_get_regulator

In current implementation, the pointer ri is not NULL if no id is matched.
Fix it by checking i == ARRAY_SIZE(aat2870_regulators) if no id is matched.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: stable@kernel.org
diff --git a/drivers/regulator/aat2870-regulator.c b/drivers/regulator/aat2870-regulator.c
index 5abeb3a..298c6c6 100644
--- a/drivers/regulator/aat2870-regulator.c
+++ b/drivers/regulator/aat2870-regulator.c
@@ -160,7 +160,7 @@
 			break;
 	}
 
-	if (!ri)
+	if (i == ARRAY_SIZE(aat2870_regulators))
 		return NULL;
 
 	ri->enable_addr = AAT2870_LDO_EN;