make do_mremap() static

The extern in sys_sparc_64.c was a rudiment of time when do_mremap()
used to exist in MMU case (it doesn't anymore).  As for !MMU one,
nothing uses it outside of mm/nommu.c...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

arch/sparc/kernel/sys_sparc_64.c

@@ -470,10 +470,6 @@ SYSCALL_DEFINE2(64_munmap, unsigned long, addr, size_t, len)
 
 	return vm_munmap(addr, len);
 }
-
-extern unsigned long do_mremap(unsigned long addr,
-	unsigned long old_len, unsigned long new_len,
-	unsigned long flags, unsigned long new_addr);
                 
 SYSCALL_DEFINE5(64_mremap, unsigned long, addr,	unsigned long, old_len,
 		unsigned long, new_len, unsigned long, flags,

include/linux/mm.h

@@ -1079,9 +1079,6 @@ extern unsigned long move_page_tables(struct vm_area_struct *vma,
 		unsigned long old_addr, struct vm_area_struct *new_vma,
 		unsigned long new_addr, unsigned long len,
 		bool need_rmap_locks);
-extern unsigned long do_mremap(unsigned long addr,
-			       unsigned long old_len, unsigned long new_len,
-			       unsigned long flags, unsigned long new_addr);
 extern unsigned long change_protection(struct vm_area_struct *vma, unsigned long start,
 			      unsigned long end, pgprot_t newprot,
 			      int dirty_accountable, int prot_numa);

mm/nommu.c

@@ -1770,7 +1770,7 @@ unsigned long vm_brk(unsigned long addr, unsigned long len)
  *
  * MREMAP_FIXED is not supported under NOMMU conditions
  */
-unsigned long do_mremap(unsigned long addr,
+static unsigned long do_mremap(unsigned long addr,
 			unsigned long old_len, unsigned long new_len,
 			unsigned long flags, unsigned long new_addr)
 {
@@ -1805,7 +1805,6 @@ unsigned long do_mremap(unsigned long addr,
 	vma->vm_end = vma->vm_start + new_len;
 	return vma->vm_start;
 }
-EXPORT_SYMBOL(do_mremap);
 
 SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len,
 		unsigned long, new_len, unsigned long, flags,