hwmon: (vt8231) Fix checkpatch issues

hwmon: (vt8231) Fix checkpatch issues

Fixed:
ERROR: code indent should use tabs where possible
ERROR: do not use assignment in if condition
ERROR: trailing statements should be on next line
WARNING: braces {} are not necessary for any arm of this statement
WARNING: line over 80 characters
WARNING: please, no space before tabs
WARNING: simple_strtol is obsolete, use kstrtol instead
WARNING: simple_strtoul is obsolete, use kstrtoul instead

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

Cc: Roger Lucas <vt8231@hiddenengine.co.uk>
Acked-by: Roger Lucas <vt8231@hiddenengine.co.uk>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>