hwmon: (thmc50) Fix checkpatch issues

Fixed:
ERROR: code indent should use tabs where possible
ERROR: do not use assignment in if condition
WARNING: simple_strtol is obsolete, use kstrtol instead
WARNING: simple_strtoul is obsolete, use kstrtoul instead

Modify multi-line comments to follow Documentation/CodingStyle.

Not fixed (false positive):
ERROR: Macros with multiple statements should be enclosed in a do - while loop

Cc: Krzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>