[NET] am79c961a: fix spin_lock usage

spin_lock functions take a pointer to the lock, not the lock itself.
This error was noticed by compiling ebsa110_defconfig for linux-rt where
the locking functions obviously are more picky about their arguments.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Roel Kluin <12o3l@tiscali.nl>
Cc: Steven Rostedt <srostedt@redhat.com>
Cc: netdev@vger.kernel.org
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>