swiotlb: use the calculated number of areas

Commit 8ac0406 ("swiotlb: reduce the number of areas to match
actual memory pool size") calculated the reduced number of areas in
swiotlb_init_remap() but didn't actually use the value. Replace usage of
default_nareas accordingly.

Fixes: 8ac0406 ("swiotlb: reduce the number of areas to match actual memory pool size")
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Author: rosslagerwall

kernel/dma/swiotlb.c

@@ -399,14 +399,13 @@ void __init swiotlb_init_remap(bool addressing_limit, unsigned int flags,
 	}
 
 	mem->areas = memblock_alloc(array_size(sizeof(struct io_tlb_area),
-		default_nareas), SMP_CACHE_BYTES);
+		nareas), SMP_CACHE_BYTES);
 	if (!mem->areas) {
 		pr_warn("%s: Failed to allocate mem->areas.\n", __func__);
 		return;
 	}
 
-	swiotlb_init_io_tlb_pool(mem, __pa(tlb), nslabs, false,
-				 default_nareas);
+	swiotlb_init_io_tlb_pool(mem, __pa(tlb), nslabs, false, nareas);
 	add_mem_pool(&io_tlb_default_mem, mem);
 
 	if (flags & SWIOTLB_VERBOSE)