[SPARC]: Initialize iounit spinlock in iounit_init().

Signed-off-by: David S. Miller <davem@davemloft.net>

arch/sparc/mm/io-unit.c

@@ -64,6 +64,7 @@ iounit_init(int sbi_node, int io_node, struct sbus_bus *sbus)
 	
 	sbus->iommu = (struct iommu_struct *)iounit;
 	iounit->page_table = xpt;
+	spin_lock_init(&iounit->lock);
 	
 	for (xptend = iounit->page_table + (16 * PAGE_SIZE) / sizeof(iopte_t);
 	     xpt < xptend;)