ACPI / table: remove duplicate NULL check for the handler of acpi_table_parse()

In acpi_table_parse(), pointer of the table to pass to handler() is
checked before handler() called, so remove all the duplicate NULL
check in the handler function.

CC: Tony Luck <tony.luck@intel.com>
CC: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/acpi/numa.c b/drivers/acpi/numa.c
index 24b5476..1333cbdc 100644
--- a/drivers/acpi/numa.c
+++ b/drivers/acpi/numa.c
@@ -177,12 +177,7 @@
 
 static int __init acpi_parse_slit(struct acpi_table_header *table)
 {
-	struct acpi_table_slit *slit;
-
-	if (!table)
-		return -EINVAL;
-
-	slit = (struct acpi_table_slit *)table;
+	struct acpi_table_slit *slit = (struct acpi_table_slit *)table;
 
 	if (!slit_valid(slit)) {
 		printk(KERN_INFO "ACPI: SLIT table looks invalid. Not used.\n");
@@ -260,11 +255,8 @@
 
 static int __init acpi_parse_srat(struct acpi_table_header *table)
 {
-	struct acpi_table_srat *srat;
-	if (!table)
-		return -EINVAL;
+	struct acpi_table_srat *srat = (struct acpi_table_srat *)table;
 
-	srat = (struct acpi_table_srat *)table;
 	acpi_srat_revision = srat->header.revision;
 
 	/* Real work done in acpi_table_parse_srat below. */