ARM: 8181/1: Drop extra return statement

Commit 513510dd
(common: dma-mapping: introduce common remapping functions)
managed to end up with an extra return statement from the
original patch. Drop it.
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mm/dma-mapping.c

@@ -1198,7 +1198,6 @@ __iommu_alloc_remap(struct page **pages, size_t size, gfp_t gfp, pgprot_t prot,
 {
 	return dma_common_pages_remap(pages, size,
 			VM_ARM_DMA_CONSISTENT | VM_USERMAP, prot, caller);
-	return NULL;
 }
 
 /*