lan78xx: Fix white space and style issues

[ Upstream commit 9ceec7d33adf9647293f24d2fd9a055b89c63864 ]

Fix white space and code style issues identified by checkpatch.

Signed-off-by: John Efstathiades <john.efstathiades@pebblebay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: 1eecc7ab82c4 ("net: lan78xx: fix runtime PM count underflow on link stop")
Signed-off-by: Sasha Levin <sashal@kernel.org>