ieee1394: add preprocessor constant for invalid csr address

Replace occurrences of the magic value ~(u64)0 for invalid
CSR address spaces by a named constant for better readability.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Ben Collins <bcollins@ubuntu.com>
diff --git a/drivers/ieee1394/highlevel.c b/drivers/ieee1394/highlevel.c
index 29c5255..165dcd6 100644
--- a/drivers/ieee1394/highlevel.c
+++ b/drivers/ieee1394/highlevel.c
@@ -301,7 +301,7 @@
 {
 	struct hpsb_address_serve *as, *a1, *a2;
 	struct list_head *entry;
-	u64 retval = ~0ULL;
+	u64 retval = CSR1212_INVALID_ADDR_SPACE;
 	unsigned long flags;
 	u64 align_mask = ~(alignment - 1);
 
@@ -314,9 +314,10 @@
 
 	/* default range,
 	 * avoids controller's posted write area (see OHCI 1.1 clause 1.5) */
-	if (start == ~0ULL && end == ~0ULL) {
+	if (start == CSR1212_INVALID_ADDR_SPACE &&
+	    end   == CSR1212_INVALID_ADDR_SPACE) {
 		start = host->middle_addr_space;
-		end = CSR1212_ALL_SPACE_END;
+		end   = CSR1212_ALL_SPACE_END;
 	}
 
 	if (((start|end) & ~align_mask) || (start >= end) || (end > 0x1000000000000ULL)) {
@@ -360,7 +361,7 @@
 
 	write_unlock_irqrestore(&addr_space_lock, flags);
 
-	if (retval == ~0ULL) {
+	if (retval == CSR1212_INVALID_ADDR_SPACE) {
 		kfree(as);
 	}