regulator: lp3972: Silence uninitialized variable warning

This is harmless but my static checker complains that "tmp" is
uninitialized if lp3972_i2c_read() fails.  I have moved the line of code
below the error handling to silence the warning.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/regulator/lp3972.c

@@ -211,8 +211,8 @@ static int lp3972_set_bits(struct lp3972 *lp3972, u8 reg, u16 mask, u16 val)
 	mutex_lock(&lp3972->io_lock);
 
 	ret = lp3972_i2c_read(lp3972->i2c, reg, 1, &tmp);
-	tmp = (tmp & ~mask) | val;
 	if (ret == 0) {
+		tmp = (tmp & ~mask) | val;
 		ret = lp3972_i2c_write(lp3972->i2c, reg, 1, &tmp);
 		dev_dbg(lp3972->dev, "reg write 0x%02x -> 0x%02x\n", (int)reg,
 			(unsigned)val & 0xff);