Revert "jfs: fix shift-out-of-bounds in dbJoin"

This reverts commit cca974da.

The added sanity check is incorrect. BUDMIN is not the wrong value and
is too small.
Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>

fs/jfs/jfs_dmap.c

@@ -2763,9 +2763,7 @@ static int dbBackSplit(dmtree_t *tp, int leafno, bool is_ctl)
  *	leafno	- the number of the leaf to be updated.
  *	newval	- the new value for the leaf.
  *
- * RETURN VALUES:
- *  0		- success
- *	-EIO	- i/o error
+ * RETURN VALUES: none
  */
 static int dbJoin(dmtree_t *tp, int leafno, int newval, bool is_ctl)
 {
@@ -2792,10 +2790,6 @@ static int dbJoin(dmtree_t *tp, int leafno, int newval, bool is_ctl)
 		 * get the buddy size (number of words covered) of
 		 * the new value.
 		 */
-
-		if ((newval - tp->dmt_budmin) > BUDMIN)
-			return -EIO;
-
 		budsz = BUDSIZE(newval, tp->dmt_budmin);
 
 		/* try to join.