hwmon: (lm75) Fix an incorrect comment

High-byte first is not opposite to the usual practice - that's what
almost all hardware monitoring drivers do. It is opposite to the SMBus
standard though.

Also delete a duplicate comment.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Mark M. Hoffman <mhoffman@lightlink.com>