i2c-dev: don't get i2c adapter via i2c_dev

There is no code protecting i2c_dev to be freed after it is returned
from i2c_dev_get_by_minor() and using it to access the value which we
already have (minor) isn't safe really.

Avoid using it and get the adapter directly from 'minor'.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Tested-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
diff --git a/drivers/i2c/i2c-dev.c b/drivers/i2c/i2c-dev.c
index 6ecfd76..66f323f 100644
--- a/drivers/i2c/i2c-dev.c
+++ b/drivers/i2c/i2c-dev.c
@@ -485,13 +485,8 @@
 	unsigned int minor = iminor(inode);
 	struct i2c_client *client;
 	struct i2c_adapter *adap;
-	struct i2c_dev *i2c_dev;
 
-	i2c_dev = i2c_dev_get_by_minor(minor);
-	if (!i2c_dev)
-		return -ENODEV;
-
-	adap = i2c_get_adapter(i2c_dev->adap->nr);
+	adap = i2c_get_adapter(minor);
 	if (!adap)
 		return -ENODEV;