hwmon: (thmc50) Fix a debug message

type_name was used before being set. See why I don't like play-it-safe
variable initializations: they prevent the compiler from warning you
about such mistakes. So fix that as well.

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