mlx4_core: fix bug in modify_cq wrapper for resize flow.

The actual FW command is called in procedure "handle_resize".
Code incorrectly invoked the FW command again (in good flow), in
the modify_cq wrapper function.

Fix by skipping second FW invocation unconditionally for resize.

Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: David S. Miller <davem@davemloft.net>