Usually, we are adding pg_temp entries or removing them.  Occasionally they
update.  In that case, osdmap_apply_incremental() was failing because the
rbtree entry already exists.
Fix by removing the existing entry before inserting a new one.
Fixes http://tracker.newdream.net/issues/2446
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
                pglen = ceph_decode_32(p);
 
                if (pglen) {
-                       /* insert */
                        ceph_decode_need(p, end, pglen*sizeof(u32), bad);
+
+                       /* removing existing (if any) */
+                       (void) __remove_pg_mapping(&map->pg_temp, pgid);
+
+                       /* insert */
                        pg = kmalloc(sizeof(*pg) + sizeof(u32)*pglen, GFP_NOFS);
                        if (!pg) {
                                err = -ENOMEM;