davinci_emac checkpatch.pl fixes

Fix checkpatch.pl bugs ... mostly return-with-parens.  And also
fix some whitespace bugs, one of which was reported by checkpatch
(bad indentation).
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>