[PATCH] implement find_extend_vma() for nommu

From: gerg@snapgear.com

Implement a null find_extend_vma() function for non-MMU architectures.  It
is called from a couple of places, so needs to be present.

mm/nommu.c

@@ -551,6 +551,11 @@ struct page * follow_page(struct mm_struct *mm, unsigned long addr, int write)
 	return NULL;
 }
 
+struct vm_area_struct *find_extend_vma(struct mm_struct *mm, unsigned long addr)
+{
+	return NULL;
+}
+
 int remap_page_range(struct vm_area_struct *vma, unsigned long from,
 		unsigned long to, unsigned long size, pgprot_t prot)
 {