powerpc: Simplify sysctl registration for nmi_wd_lpm_factor_ctl_table

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>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230310232850.3960676-3-mcgrof@kernel.org

arch/powerpc/platforms/pseries/mobility.c

@@ -62,18 +62,10 @@ static struct ctl_table nmi_wd_lpm_factor_ctl_table[] = {
 	},
 	{}
 };
-static struct ctl_table nmi_wd_lpm_factor_sysctl_root[] = {
-	{
-		.procname       = "kernel",
-		.mode           = 0555,
-		.child          = nmi_wd_lpm_factor_ctl_table,
-	},
-	{}
-};
 
 static int __init register_nmi_wd_lpm_factor_sysctl(void)
 {
-	register_sysctl_table(nmi_wd_lpm_factor_sysctl_root);
+	register_sysctl("kernel", nmi_wd_lpm_factor_ctl_table);
 
 	return 0;
 }