nios2: remove __iounmap

No need to indirect iounmap for nios2.

Signed-off-by: Christoph Hellwig <[e-mail]>

arch/nios2/include/asm/io.h

···
 #define writel_relaxed(x, addr)	writel(x, addr)
 
 void __iomem *ioremap(unsigned long physaddr, unsigned long size);
-extern void __iounmap(void __iomem *addr);
-
-static inline void iounmap(void __iomem *addr)
-{
-	__iounmap(addr);
-}
+void iounmap(void __iomem *addr);
 
 /* Pages to physical address... */
 #define page_to_phys(page)	virt_to_phys(page_to_virt(page))

arch/nios2/mm/ioremap.c

···
 EXPORT_SYMBOL(ioremap);
 
 /*
- * __iounmap unmaps nearly everything, so be careful
+ * iounmap unmaps nearly everything, so be careful
  * it doesn't free currently pointer/page tables anymore but it
  * wasn't used anyway and might be added later.
  */
-void __iounmap(void __iomem *addr)
+void iounmap(void __iomem *addr)
 {
 	struct vm_struct *p;
 
···
 		pr_err("iounmap: bad address %p\n", addr);
 	kfree(p);
 }
-EXPORT_SYMBOL(__iounmap);
+EXPORT_SYMBOL(iounmap);