iwlwifi: pcie: replace possible_cpus() with online_cpus() in MSIX mode

In MSIX mode the number of irq depends on the number of
possible cpus existing on the host.
This cause to bug in case there are offline cores.
Take into account only the online CPUs instead.
Also save it in temporary variable.

Fixes: commit 2e5d4a8f61dc ("iwlwifi: pcie: Add new configuration to enable MSIX")
Signed-off-by: Haim Dreyfuss <haim.dreyfuss@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>

drivers/net/wireless/intel/iwlwifi/pcie/trans.c

@@ -1513,13 +1513,14 @@ static void iwl_pcie_set_interrupt_capa(struct pci_dev *pdev,
 					struct iwl_trans *trans)
 {
 	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
-	int max_irqs, num_irqs, i, ret;
+	int max_irqs, num_irqs, i, ret, nr_online_cpus;
 	u16 pci_cmd;
 
 	if (!trans->cfg->mq_rx_supported)
 		goto enable_msi;
 
-	max_irqs = min_t(u32, num_possible_cpus() + 2, IWL_MAX_RX_HW_QUEUES);
+	nr_online_cpus = num_online_cpus();
+	max_irqs = min_t(u32, nr_online_cpus + 2, IWL_MAX_RX_HW_QUEUES);
 	for (i = 0; i < max_irqs; i++)
 		trans_pcie->msix_entries[i].entry = i;
 
@@ -1545,11 +1546,11 @@ static void iwl_pcie_set_interrupt_capa(struct pci_dev *pdev,
 	 * Two interrupts less: non rx causes shared with FBQ and RSS.
 	 * More than two interrupts: we will use fewer RSS queues.
 	 */
-	if (num_irqs <= num_online_cpus()) {
+	if (num_irqs <= nr_online_cpus) {
 		trans_pcie->trans->num_rx_queues = num_irqs + 1;
 		trans_pcie->shared_vec_mask = IWL_SHARED_IRQ_NON_RX |
 			IWL_SHARED_IRQ_FIRST_RSS;
-	} else if (num_irqs == num_online_cpus() + 1) {
+	} else if (num_irqs == nr_online_cpus + 1) {
 		trans_pcie->trans->num_rx_queues = num_irqs;
 		trans_pcie->shared_vec_mask = IWL_SHARED_IRQ_NON_RX;
 	} else {