x86: simplify one-level sysctl registration for abi_table2

There is no need to declare an extra tables to just create directory,
this can be easily be done with a prefix path with register_sysctl().

Simplify this registration.

Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>

arch/x86/entry/vdso/vdso32-setup.c

@@ -70,18 +70,9 @@ static struct ctl_table abi_table2[] = {
 	{}
 };
 
-static struct ctl_table abi_root_table2[] = {
-	{
-		.procname = "abi",
-		.mode = 0555,
-		.child = abi_table2
-	},
-	{}
-};
-
 static __init int ia32_binfmt_init(void)
 {
-	register_sysctl_table(abi_root_table2);
+	register_sysctl("abi", abi_table2);
 	return 0;
 }
 __initcall(ia32_binfmt_init);