x86: fix bogus memcpy in es7000_check_dsdt()

es7000_check_dst() contains a memcpy from 0, which probably should have been
a memset. Remove it and check the retunr value from acpi_get_table_header.

Noticed by: Joe Perches <joe@perches.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

include/asm-x86/mach-es7000/mach_mpparse.h

@@ -29,9 +29,9 @@ extern int mps_oem_check(struct mp_config_table *mpc, char *oem,
 static inline int es7000_check_dsdt(void)
 {
 	struct acpi_table_header header;
-	memcpy(&header, 0, sizeof(struct acpi_table_header));
-	acpi_get_table_header(ACPI_SIG_DSDT, 0, &header);
-	if (!strncmp(header.oem_id, "UNISYS", 6))
+
+	if (ACPI_SUCCESS(acpi_get_table_header(ACPI_SIG_DSDT, 0, &header)) &&
+	    !strncmp(header.oem_id, "UNISYS", 6))
 		return 1;
 	return 0;
 }