ACPICA: Fix table entry truncation calculation

During early boot, ACPI RSDT/XSDT table entries are gathered into the
'initial_tables[]' array.  This array is currently statically defined (see
./drivers/acpi/tables.c).  When there are more table entries than can be
held in the 'initial_tables[]' array, the message "Truncating N table
entries!" is output.  As currently implemented, this message will always
erroneously calculate N as 0.

This patch fixes the calculation that determines how many table entries
will be missing (truncated).

This modification may be used under either the GPL or the BSD-style
license used for Intel ACPI CA code.

Signed-off-by: Myron Stowe <myron.stowe@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/acpi/acpica/tbutils.c

@@ -538,10 +538,9 @@ acpi_tb_parse_root_table(acpi_physical_address rsdp_address, u8 flags)
 			if (ACPI_FAILURE(status)) {
 				ACPI_WARNING((AE_INFO,
 					      "Truncating %u table entries!",
-					      (unsigned)
-					      (acpi_gbl_root_table_list.size -
-					       acpi_gbl_root_table_list.
-					       count)));
+					      (unsigned) (table_count -
+					       (acpi_gbl_root_table_list.
+					       count - 2))));
 				break;
 			}
 		}