ixgbe: Be explict with what we are !'ing in ixgbe_sfp_config_module_task()

GCC warns:
drivers/net/ixgbe/ixgbe_main.c: In function 'ixgbe_sfp_config_module_task':
drivers/net/ixgbe/ixgbe_main.c:3920: warning: suggest parantheses around
operand of '!' or change '&' to '&&' or '!' to '~'

Which I think is right.  Bracket to remove ambiguity.
Signed-off-by: NTony Breeds <tony@bakeyournoodle.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ixgbe/ixgbe_main.c

@@ -3917,7 +3917,7 @@ static void ixgbe_sfp_config_module_task(struct work_struct *work)
 	}
 	hw->mac.ops.setup_sfp(hw);
 
-	if (!adapter->flags & IXGBE_FLAG_IN_SFP_LINK_TASK)
+	if (!(adapter->flags & IXGBE_FLAG_IN_SFP_LINK_TASK))
 		/* This will also work for DA Twinax connections */
 		schedule_work(&adapter->multispeed_fiber_task);
 	adapter->flags &= ~IXGBE_FLAG_IN_SFP_MOD_TASK;