powerpc/rtas: move syscall filter setup into separate function

Reduce conditionally compiled sections within rtas_initialize() by
moving the filter table initialization into its own function already
guarded by CONFIG_PPC_RTAS_FILTER. No behavior change intended.
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Acked-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210408140630.205502-5-nathanl@linux.ibm.com

arch/powerpc/kernel/rtas.c

@@ -1051,6 +1051,14 @@ static bool block_rtas_call(int token, int nargs,
 	return true;
 }
 
+static void __init rtas_syscall_filter_init(void)
+{
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(rtas_filters); i++)
+		rtas_filters[i].token = rtas_token(rtas_filters[i].name);
+}
+
 #else
 
 static bool block_rtas_call(int token, int nargs,
@@ -1059,6 +1067,10 @@ static bool block_rtas_call(int token, int nargs,
 	return false;
 }
 
+static void __init rtas_syscall_filter_init(void)
+{
+}
+
 #endif /* CONFIG_PPC_RTAS_FILTER */
 
 /* We assume to be passed big endian arguments */
@@ -1162,9 +1174,6 @@ void __init rtas_initialize(void)
 	unsigned long rtas_region = RTAS_INSTANTIATE_MAX;
 	u32 base, size, entry;
 	int no_base, no_size, no_entry;
-#ifdef CONFIG_PPC_RTAS_FILTER
-	int i;
-#endif
 
 	/* Get RTAS dev node and fill up our "rtas" structure with infos
 	 * about it.
@@ -1203,11 +1212,7 @@ void __init rtas_initialize(void)
 	rtas_last_error_token = rtas_token("rtas-last-error");
 #endif
 
-#ifdef CONFIG_PPC_RTAS_FILTER
-	for (i = 0; i < ARRAY_SIZE(rtas_filters); i++) {
-		rtas_filters[i].token = rtas_token(rtas_filters[i].name);
-	}
-#endif
+	rtas_syscall_filter_init();
 }
 
 int __init early_init_dt_scan_rtas(unsigned long node,