ACPI: fix build warning

CC drivers/acpi/executer/exregion.o
drivers/acpi/executer/exregion.c: In function
‘acpi_ex_pci_config_space_handler’:
drivers/acpi/executer/exregion.c:369: attention : passing argument 3 of
‘acpi_os_read_pci_configuration’ from incompatible pointer type

exposed by 10270d4838bdc493781f5a1cf2e90e9c34c9142f

http://bugzilla.kernel.org/show_bug.cgi?id=9989

Signed-off-by: Ming Lin <[e-mail]>
Signed-off-by: Len Brown <[e-mail]>

drivers/acpi/executer/exregion.c

···
 	acpi_status status = AE_OK;
 	struct acpi_pci_id *pci_id;
 	u16 pci_register;
+	u32 value32;
 
 	ACPI_FUNCTION_TRACE(ex_pci_config_space_handler);
 
···
 	switch (function) {
 	case ACPI_READ:
 
-		*value = 0;
 		status = acpi_os_read_pci_configuration(pci_id, pci_register,
-							value, bit_width);
+							&value32, bit_width);
+		*value = value32;
 		break;
 
 	case ACPI_WRITE: