Don't insert before existing chunk into the hash.

This code branch is never used (because exceptions are allocated consecutevely)
and if it were used, it would break snapshot merging.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>

Index: linux-2.6.26-rc5-devel/drivers/md/dm-snap.c
===================================================================
--- linux-2.6.26-rc5-devel.orig/drivers/md/dm-snap.c	2008-06-16 21:39:46.000000000 +0200
+++ linux-2.6.26-rc5-devel/drivers/md/dm-snap.c	2008-06-16 21:47:24.000000000 +0200
@@ -393,16 +393,6 @@
 			return;
 		}
 
-		/* Insert before an existing chunk? */
-		if (new_e->old_chunk == (e->old_chunk - 1) &&
-		    new_e->new_chunk == (dm_chunk_number(e->new_chunk) - 1)) {
-			dm_consecutive_chunk_count_inc(e);
-			e->old_chunk--;
-			e->new_chunk--;
-			free_exception(new_e);
-			return;
-		}
-
 		if (new_e->old_chunk > e->old_chunk)
 			break;
 	}