igc: field prep conversion

Refactor igc driver to use FIELD_PREP(), which reduces lines of code
and adds clarity of intent.

This code was generated by the following coccinelle/spatch script and
then manually repaired in a later patch.

@prep2@
constant shift,mask;
type T;
expression a;
@@
-(((T)(a) << shift) & mask)
+FIELD_PREP(mask, a)

@prep@
constant shift,mask;
type T;
expression a;
@@
-((T)((a) << shift) & mask)
+FIELD_PREP(mask, a)

Cc: Julia Lawall <Julia.Lawall@inria.fr>
Cc: Sasha Neftin <sasha.neftin@intel.com>
Reviewed-by: Marcin Szycik <marcin.szycik@linux.intel.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

drivers/net/ethernet/intel/igc/igc_main.c

@@ -3452,8 +3452,8 @@ static int igc_write_flex_filter_ll(struct igc_adapter *adapter,
 
 	/* Configure filter */
 	queuing = input->length & IGC_FHFT_LENGTH_MASK;
-	queuing |= (input->rx_queue << IGC_FHFT_QUEUE_SHIFT) & IGC_FHFT_QUEUE_MASK;
-	queuing |= (input->prio << IGC_FHFT_PRIO_SHIFT) & IGC_FHFT_PRIO_MASK;
+	queuing |= FIELD_PREP(IGC_FHFT_QUEUE_MASK, input->rx_queue);
+	queuing |= FIELD_PREP(IGC_FHFT_PRIO_MASK, input->prio);
 
 	if (input->immediate_irq)
 		queuing |= IGC_FHFT_IMM_INT;