PCI: hv: Allocate interrupt descriptors with GFP_ATOMIC

The memory allocation here needs to be non-blocking.  Fix the issue.
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Long Li <longli@microsoft.com>
Cc: <stable@vger.kernel.org>

drivers/pci/host/pci-hyperv.c

@@ -878,7 +878,7 @@ static void hv_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
 		hv_int_desc_free(hpdev, int_desc);
 	}
 
-	int_desc = kzalloc(sizeof(*int_desc), GFP_KERNEL);
+	int_desc = kzalloc(sizeof(*int_desc), GFP_ATOMIC);
 	if (!int_desc)
 		goto drop_reference;