ACPI: resource: Fix memory resource type union access

In acpi_decode_space() addr->info.mem.caching is checked on main level
for any resource type but addr->info.mem is part of union and thus
valid only if the resource type is memory range.

Move the check inside the preceeding switch/case to only execute it
when the union is of correct type.

Fixes: fcb29bb ("ACPI: Add prefetch decoding to the address space parser")
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://patch.msgid.link/20241202100614.20731-1-ilpo.jarvinen@linux.intel.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Author: ij-intel

drivers/acpi/resource.c

@@ -250,6 +250,9 @@ static bool acpi_decode_space(struct resource_win *win,
 	switch (addr->resource_type) {
 	case ACPI_MEMORY_RANGE:
 		acpi_dev_memresource_flags(res, len, wp);
+
+		if (addr->info.mem.caching == ACPI_PREFETCHABLE_MEMORY)
+			res->flags |= IORESOURCE_PREFETCH;
 		break;
 	case ACPI_IO_RANGE:
 		acpi_dev_ioresource_flags(res, len, iodec,
@@ -265,9 +268,6 @@ static bool acpi_decode_space(struct resource_win *win,
 	if (addr->producer_consumer == ACPI_PRODUCER)
 		res->flags |= IORESOURCE_WINDOW;
 
-	if (addr->info.mem.caching == ACPI_PREFETCHABLE_MEMORY)
-		res->flags |= IORESOURCE_PREFETCH;
-
 	return !(res->flags & IORESOURCE_DISABLED);
 }