nios2: use correct void* return type for page_to_virt()

To align with other architectures, the expression produced by expanding
the macro page_to_virt() should be of type void*, since it returns a
virtual address. Fix that, and also fix up an instance where page_to_virt
was expected to return 'unsigned long', and drop another instance that was
entirely unused (page_to_bus)

Acked-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
diff --git a/arch/nios2/include/asm/page.h b/arch/nios2/include/asm/page.h
index 4b32d6f..c1683f5 100644
--- a/arch/nios2/include/asm/page.h
+++ b/arch/nios2/include/asm/page.h
@@ -84,7 +84,7 @@
 	((void *)((unsigned long)(x) + PAGE_OFFSET - PHYS_OFFSET))
 
 #define page_to_virt(page)	\
-	((((page) - mem_map) << PAGE_SHIFT) + PAGE_OFFSET)
+	((void *)(((page) - mem_map) << PAGE_SHIFT) + PAGE_OFFSET)
 
 # define pfn_to_kaddr(pfn)	__va((pfn) << PAGE_SHIFT)
 # define pfn_valid(pfn)		((pfn) >= ARCH_PFN_OFFSET &&	\