wifi: ath12k: Remove redundant pci_clear_master

Remove pci_clear_master to simplify the code,
the bus-mastering is also cleared in do_pci_disable_device,
like this:
./drivers/pci/pci.c:2197
static void do_pci_disable_device(struct pci_dev *dev)
{
	u16 pci_command;

	pci_read_config_word(dev, PCI_COMMAND, &pci_command);
	if (pci_command & PCI_COMMAND_MASTER) {
		pci_command &= ~PCI_COMMAND_MASTER;
		pci_write_config_word(dev, PCI_COMMAND, pci_command);
	}

	pcibios_disable_device(dev);
}.
And dev->is_busmaster is set to 0 in pci_disable_device.
Signed-off-by: Cai Huoqing <cai.huoqing@linux.dev>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20230323112613.7550-3-cai.huoqing@linux.dev

drivers/net/wireless/ath/ath12k/pci.c

@@ -755,14 +755,12 @@ static int ath12k_pci_claim(struct ath12k_pci *ab_pci, struct pci_dev *pdev)
 	if (!ab->mem) {
 		ath12k_err(ab, "failed to map pci bar %d\n", ATH12K_PCI_BAR_NUM);
 		ret = -EIO;
-		goto clear_master;
+		goto release_region;
 	}
 
 	ath12k_dbg(ab, ATH12K_DBG_BOOT, "boot pci_mem 0x%pK\n", ab->mem);
 	return 0;
 
-clear_master:
-	pci_clear_master(pdev);
 release_region:
 	pci_release_region(pdev, ATH12K_PCI_BAR_NUM);
 disable_device:
@@ -778,7 +776,6 @@ static void ath12k_pci_free_region(struct ath12k_pci *ab_pci)
 
 	pci_iounmap(pci_dev, ab->mem);
 	ab->mem = NULL;
-	pci_clear_master(pci_dev);
 	pci_release_region(pci_dev, ATH12K_PCI_BAR_NUM);
 	if (pci_is_enabled(pci_dev))
 		pci_disable_device(pci_dev);