i2o: fix simple_return.cocci warnings

drivers/staging/i2o/iop.c:777:1-3: WARNING: end returns can be simpified

 Simplify a trivial if-return sequence.  Possibly combine with a
 preceding function call.
Generated by: scripts/coccinelle/misc/simple_return.cocci

CC: Alan Cox <alan@linux.intel.com>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/i2o/iop.c

@@ -777,11 +777,7 @@ static int i2o_iop_online(struct i2o_controller *c)
 
 	/* In READY state */
 	osm_debug("%s: Attempting to enable...\n", c->name);
-	rc = i2o_iop_enable(c);
-	if (rc)
-		return rc;
-
-	return 0;
+	return i2o_iop_enable(c);
 }
 
 /**