ia64, sparc64: convert wrappers around do_mremap() to sys_mremap()

they contain open-coded sys_mremap()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

arch/ia64/kernel/sys_ia64.c

@@ -171,22 +171,9 @@ asmlinkage unsigned long
 ia64_mremap (unsigned long addr, unsigned long old_len, unsigned long new_len, unsigned long flags,
 	     unsigned long new_addr)
 {
-	extern unsigned long do_mremap (unsigned long addr,
-					unsigned long old_len,
-					unsigned long new_len,
-					unsigned long flags,
-					unsigned long new_addr);
-
-	down_write(&current->mm->mmap_sem);
-	{
-		addr = do_mremap(addr, old_len, new_len, flags, new_addr);
-	}
-	up_write(&current->mm->mmap_sem);
-
-	if (IS_ERR((void *) addr))
-		return addr;
-
-	force_successful_syscall_return();
+	addr = sys_mremap(addr, old_len, new_len, flags, new_addr);
+	if (!IS_ERR((void *) addr))
+		force_successful_syscall_return();
 	return addr;
 }
 

arch/sparc/kernel/sys_sparc_64.c

@@ -580,16 +580,9 @@ SYSCALL_DEFINE5(64_mremap, unsigned long, addr,	unsigned long, old_len,
 		unsigned long, new_len, unsigned long, flags,
 		unsigned long, new_addr)
 {
-	unsigned long ret = -EINVAL;
-
 	if (test_thread_flag(TIF_32BIT))
-		goto out;
-
-	down_write(&current->mm->mmap_sem);
-	ret = do_mremap(addr, old_len, new_len, flags, new_addr);
-	up_write(&current->mm->mmap_sem);
-out:
-	return ret;       
+		return -EINVAL;
+	return sys_mremap(addr, old_len, new_len, flags, new_addr);
 }
 
 /* we come to here via sys_nis_syscall so it can setup the regs argument */