hwmon: (pmbus/hac300s) Add error check for pmbus_read_word_data() return value

hac300s_read_word_data() passes the return value of pmbus_read_word_data()
directly to FIELD_GET() without checking for errors. If the I2C transaction
fails, a negative error code is sign-extended and passed to FIELD_GET(),
which silently produces garbage data instead of propagating the error.

Add the missing error check before using the return value in
the FIELD_GET() macro.

Fixes: 669cf16 ("hwmon: Add support for HiTRON HAC300S PSU")
Cc: [email protected]
Signed-off-by: Sanman Pradhan <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Guenter Roeck <[email protected]>

Author: Sanman Pradhan

drivers/hwmon/pmbus/hac300s.c

@@ -58,6 +58,8 @@ static int hac300s_read_word_data(struct i2c_client *client, int page,
 	case PMBUS_MFR_VOUT_MIN:
 	case PMBUS_READ_VOUT:
 		rv = pmbus_read_word_data(client, page, phase, reg);
+		if (rv < 0)
+			return rv;
 		return FIELD_GET(LINEAR11_MANTISSA_MASK, rv);
 	default:
 		return -ENODATA;