vmalloc: add const to void* parameters

Make vmalloc functions work the same way as kfree() and friends that
take a const void * argument.

[akpm@linux-foundation.org: fix consts, coding-style]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 1961056..a862a96 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -232,8 +232,8 @@
 }
 
 /* Support for virtually mapped pages */
-struct page *vmalloc_to_page(void *addr);
-unsigned long vmalloc_to_pfn(void *addr);
+struct page *vmalloc_to_page(const void *addr);
+unsigned long vmalloc_to_pfn(const void *addr);
 
 static inline struct page *compound_head(struct page *page)
 {