cleanup: code style fixes

Remove trailing whitespaces and tabs.
Enclose value in return statements in parentheses.
Use tabs after #define.
Do not skip comparison with 0/NULL in boolean expressions.

Submitted by:   Andrew Rybchenko <arybchenko at solarflare.com>
Sponsored by:   Solarflare Communications, Inc.


git-svn-id: svn+ssh://svn.freebsd.org/base/head@272325 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f