hwmon: (w83791d) Fix checkpatch issues

Fixed:
ERROR: code indent should use tabs where possible
ERROR: do not use assignment in if condition
ERROR: space prohibited after that open parenthesis '('
ERROR: space required after that ',' (ctx:VxV)
WARNING: braces {} are not necessary for single statement blocks
WARNING: simple_strtol is obsolete, use kstrtol instead
WARNING: simple_strtoul is obsolete, use kstrtoul instead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 complex values should be enclosed in parenthesis

Cc: Charles Spirakis <bezaur@gmail.com>
Cc: Marc Hulsman <m.hulsman@tudelft.nl>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>