regulator: lp3971: Silence uninitialized variable warning

This is harmless but if lp3971_i2c_read() fails then "tmp" can be
uninitialized.  Silence the warning by moving the error handling up a
line.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/regulator/lp3971.c

@@ -365,8 +365,8 @@ static int lp3971_set_bits(struct lp3971 *lp3971, u8 reg, u16 mask, u16 val)
 	mutex_lock(&lp3971->io_lock);
 
 	ret = lp3971_i2c_read(lp3971->i2c, reg, 1, &tmp);
-	tmp = (tmp & ~mask) | val;
 	if (ret == 0) {
+		tmp = (tmp & ~mask) | val;
 		ret = lp3971_i2c_write(lp3971->i2c, reg, 1, &tmp);
 		dev_dbg(lp3971->dev, "reg write 0x%02x -> 0x%02x\n", (int)reg,
 			(unsigned)val&0xff);