pata_hpt3x2n: coding style cleanup

Fix 8 errors and 3 warnings given by checkpatch.pl:

- *switch* and *case* not on the same indentation level;

- no space between *for*/*switch*/*while* and open parenthesis;

- space between an unary operator and its operand;

- spaces before tabs;

- lines over 80 characters.

In addition to these changes, also do the following:

- add new line after variable definitions;

- fix the style of some multi-line comments.

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>