ice: Use bitmap_free() to free bitmap

kfree() and bitmap_free() are the same. But using the latter is more
consistent when freeing memory allocated with bitmap_zalloc().

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Tested-by: Gurucharan G <gurucharanx.g@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

drivers/net/ethernet/intel/ice/ice_ptp.c

@@ -2229,7 +2229,7 @@ ice_ptp_release_tx_tracker(struct ice_pf *pf, struct ice_ptp_tx *tx)
 	kfree(tx->tstamps);
 	tx->tstamps = NULL;
 
-	kfree(tx->in_use);
+	bitmap_free(tx->in_use);
 	tx->in_use = NULL;
 
 	tx->len = 0;