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>

arch/ia64/kernel/acpi.c

@@ -380,9 +380,6 @@ static void __init acpi_madt_oem_check(char *oem_id, char *oem_table_id)
 
 static int __init acpi_parse_madt(struct acpi_table_header *table)
 {
-	if (!table)
-		return -EINVAL;
-
 	acpi_madt = (struct acpi_table_madt *)table;
 
 	acpi_madt_rev = acpi_madt->header.revision;
@@ -645,9 +642,6 @@ static int __init acpi_parse_fadt(struct acpi_table_header *table)
 	struct acpi_table_header *fadt_header;
 	struct acpi_table_fadt *fadt;
 
-	if (!table)
-		return -EINVAL;
-
 	fadt_header = (struct acpi_table_header *)table;
 	if (fadt_header->revision != 3)
 		return -ENODEV;	/* Only deal with ACPI 2.0 FADT */

arch/x86/kernel/acpi/boot.c

@@ -843,13 +843,7 @@ int acpi_ioapic_registered(acpi_handle handle, u32 gsi_base)
 
 static int __init acpi_parse_sbf(struct acpi_table_header *table)
 {
-	struct acpi_table_boot *sb;
-
-	sb = (struct acpi_table_boot *)table;
-	if (!sb) {
-		printk(KERN_WARNING PREFIX "Unable to map SBF\n");
-		return -ENODEV;
-	}
+	struct acpi_table_boot *sb = (struct acpi_table_boot *)table;
 
 	sbf_port = sb->cmos_index;	/* Save CMOS port */
 
@@ -863,13 +857,7 @@ static struct resource *hpet_res __initdata;
 
 static int __init acpi_parse_hpet(struct acpi_table_header *table)
 {
-	struct acpi_table_hpet *hpet_tbl;
-
-	hpet_tbl = (struct acpi_table_hpet *)table;
-	if (!hpet_tbl) {
-		printk(KERN_WARNING PREFIX "Unable to map HPET\n");
-		return -ENODEV;
-	}
+	struct acpi_table_hpet *hpet_tbl = (struct acpi_table_hpet *)table;
 
 	if (hpet_tbl->address.space_id != ACPI_SPACE_MEM) {
 		printk(KERN_WARNING PREFIX "HPET timers must be located in "

drivers/acpi/numa.c

@@ -177,12 +177,7 @@ static int __init slit_valid(struct acpi_table_slit *slit)
 
 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 @@ acpi_parse_memory_affinity(struct acpi_subtable_header * header,
 
 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. */