tile: avoid struct vm_struct leak

If ioreamp_prot() fails in ioremap_page_range() due to kernel memory
exhaustion, we previously would leak a struct vm_struct.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

arch/tile/mm/pgtable.c

@@ -568,7 +568,7 @@ void __iomem *ioremap_prot(resource_size_t phys_addr, unsigned long size,
 	addr = area->addr;
 	if (ioremap_page_range((unsigned long)addr, (unsigned long)addr + size,
 			       phys_addr, pgprot)) {
-		remove_vm_area((void *)(PAGE_MASK & (unsigned long) addr));
+		free_vm_area(area);
 		return NULL;
 	}
 	return (__force void __iomem *) (offset + (char *)addr);