staging: octeon-ethernet: make global_register_lock static

Make global_register_lock static to eliminate a sparse warning.
Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/octeon/ethernet-rgmii.c

@@ -43,7 +43,7 @@
 #include <asm/octeon/cvmx-npi-defs.h>
 #include <asm/octeon/cvmx-gmxx-defs.h>
 
-DEFINE_SPINLOCK(global_register_lock);
+static DEFINE_SPINLOCK(global_register_lock);
 
 static int number_rgmii_ports;