ACPI, APEI, Fix ERST header length check

This fixes a trivial copy & paste error in ERST header length check.
It's just for future safety because sizeof(struct acpi_table_einj)
equals to sizeof(struct acpi_table_erst) with current ACPI5.0
specification. It applies to v3.3-rc6.

Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Acked-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/acpi/apei/erst.c

@@ -917,7 +917,7 @@ static int erst_check_table(struct acpi_table_erst *erst_tab)
 {
 	if ((erst_tab->header_length !=
 	     (sizeof(struct acpi_table_erst) - sizeof(erst_tab->header)))
-	    && (erst_tab->header_length != sizeof(struct acpi_table_einj)))
+	    && (erst_tab->header_length != sizeof(struct acpi_table_erst)))
 		return -EINVAL;
 	if (erst_tab->header.length < sizeof(struct acpi_table_erst))
 		return -EINVAL;