ACPI: OSL: Rework acpi_check_resource_conflict()

Rearrange the code in acpi_check_resource_conflict() so as to drop
redundant checks and uneeded local variables from there and modify
the messages printed by that function to be more concise and
hopefully easier to understand.

While at it, replace direct printk() usage with pr_*().
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/osl.c

@@ -1458,38 +1458,28 @@ __setup("acpi_enforce_resources=", acpi_enforce_resources_setup);
 int acpi_check_resource_conflict(const struct resource *res)
 {
 	acpi_adr_space_type space_id;
-	acpi_size length;
-	u8 warn = 0;
-	int clash = 0;
 
 	if (acpi_enforce_resources == ENFORCE_RESOURCES_NO)
 		return 0;
-	if (!(res->flags & IORESOURCE_IO) && !(res->flags & IORESOURCE_MEM))
-		return 0;
 
 	if (res->flags & IORESOURCE_IO)
 		space_id = ACPI_ADR_SPACE_SYSTEM_IO;
-	else
+	else if (res->flags & IORESOURCE_MEM)
 		space_id = ACPI_ADR_SPACE_SYSTEM_MEMORY;
+	else
+		return 0;
 
-	length = resource_size(res);
-	if (acpi_enforce_resources != ENFORCE_RESOURCES_NO)
-		warn = 1;
-	clash = acpi_check_address_range(space_id, res->start, length, warn);
+	if (!acpi_check_address_range(space_id, res->start, resource_size(res), 1))
+		return 0;
+
+	pr_info("Resource conflict; ACPI support missing from driver?\n");
 
-	if (clash) {
-		if (acpi_enforce_resources != ENFORCE_RESOURCES_NO) {
-			if (acpi_enforce_resources == ENFORCE_RESOURCES_LAX)
-				printk(KERN_NOTICE "ACPI: This conflict may"
-				       " cause random problems and system"
-				       " instability\n");
-			printk(KERN_INFO "ACPI: If an ACPI driver is available"
-			       " for this device, you should use it instead of"
-			       " the native driver\n");
-		}
 	if (acpi_enforce_resources == ENFORCE_RESOURCES_STRICT)
 		return -EBUSY;
-	}
+
+	if (acpi_enforce_resources == ENFORCE_RESOURCES_LAX)
+		pr_notice("Resource conflict: System may be unstable or behave erratically\n");
+
 	return 0;
 }
 EXPORT_SYMBOL(acpi_check_resource_conflict);