avr32: Remove useless zeroing of swapper_pg_dir at startup

swapper_pg_dir is stored in .bss, so it must already be zeroed out
when we get there.
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>

arch/avr32/mm/init.c

@@ -108,19 +108,9 @@ void __init paging_init(void)
 	zero_page = alloc_bootmem_low_pages_node(NODE_DATA(0),
 						 PAGE_SIZE);
 
-	{
-		pgd_t *pg_dir;
-		int i;
-
-		pg_dir = swapper_pg_dir;
-		sysreg_write(PTBR, (unsigned long)pg_dir);
-
-		for (i = 0; i < PTRS_PER_PGD; i++)
-			pgd_val(pg_dir[i]) = 0;
-
+	sysreg_write(PTBR, (unsigned long)swapper_pg_dir);
 	enable_mmu();
 	printk ("CPU: Paging enabled\n");
-	}
 
 	for_each_online_node(nid) {
 		pg_data_t *pgdat = NODE_DATA(nid);