[MTD] Define and use MTD_FAIL_ADDR_UNKNOWN instead of 0xffffffff

Signed-off-by: Adrian Hunter <ext-adrian.hunter@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
diff --git a/drivers/mtd/mtdconcat.c b/drivers/mtd/mtdconcat.c
index 2972a5e..789842d 100644
--- a/drivers/mtd/mtdconcat.c
+++ b/drivers/mtd/mtdconcat.c
@@ -444,7 +444,7 @@
 			return -EINVAL;
 	}
 
-	instr->fail_addr = 0xffffffff;
+	instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
 
 	/* make a local copy of instr to avoid modifying the caller's struct */
 	erase = kmalloc(sizeof (struct erase_info), GFP_KERNEL);
@@ -493,7 +493,7 @@
 			/* sanity check: should never happen since
 			 * block alignment has been checked above */
 			BUG_ON(err == -EINVAL);
-			if (erase->fail_addr != 0xffffffff)
+			if (erase->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
 				instr->fail_addr = erase->fail_addr + offset;
 			break;
 		}