i40e: avoid disable of interrupt when changing ITR

i40e: avoid disable of interrupt when changing ITR

The call to irq_dynamic_disable was turning off the interrupt completely
when trying to set ITR to 0 (for lowest moderation).  Just remove the
call as setting the values to 0 later in this function will suffice.

Change-ID: I47caf1ecbe65653cf63ec833db93094cd83fd84d
Signed-off-by: Jesse Brandeburg <[email protected]>
Signed-off-by: Patrick Lu <[email protected]>
Tested-By: Jim Young <[email protected]>
Signed-off-by: Jeff Kirsher <[email protected]>