i2c: Simplify i2c_parent_is_i2c_adapter

Only i2c devices can have their type set to i2c_adapter_type, so
testing the bus type is redundant.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Michael Lawnick <ml.lawnick@gmx.de>

include/linux/i2c.h

@@ -387,7 +387,6 @@ static inline void i2c_set_adapdata(struct i2c_adapter *dev, void *data)
 static inline int i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter)
 {
 	return adapter->dev.parent != NULL
-		&& adapter->dev.parent->bus == &i2c_bus_type
 		&& adapter->dev.parent->type == &i2c_adapter_type;
 }