i40evf: clean up local variable initialization

i40evf: clean up local variable initialization

Orabug: 22342532

In i40evf_msix_aq(), the first two lines of rd32() are mainly to clear
the registers. If we initialize 'val' at this point, it will be
overwritten immediately. We shall simply discard the return value here.

When we initialize 'val', we might as well include the mask in one step.

Signed-off-by: Jean Sacren <sakiwit@gmail.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
(cherry picked from commit ed17f7e5d7918adb487debe49fadf57fd2b98d1c)
Signed-off-by: Brian Maly <brian.maly@oracle.com>