hv_netvsc: make netvsc_destroy_buf void

BugLink: http://bugs.launchpad.net/bugs/1650059

No caller checks the return value.
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 7a2a0a84)
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Acked-by: Brad Figg <brad.figg@canonical.com>
Acked-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

drivers/net/hyperv/netvsc.c

@@ -206,12 +206,12 @@ static struct netvsc_device *get_inbound_net_device(struct hv_device *device)
 	return net_device;
 }
 
-static int netvsc_destroy_buf(struct hv_device *device)
+static void netvsc_destroy_buf(struct hv_device *device)
 {
 	struct nvsp_message *revoke_packet;
-	int ret = 0;
 	struct net_device *ndev = hv_get_drvdata(device);
 	struct netvsc_device *net_device = net_device_to_netvsc_device(ndev);
+	int ret;
 
 	/*
 	 * If we got a section count, it means we received a
@@ -241,7 +241,7 @@ static int netvsc_destroy_buf(struct hv_device *device)
 		if (ret != 0) {
 			netdev_err(ndev, "unable to send "
 				"revoke receive buffer to netvsp\n");
-			return ret;
+			return;
 		}
 	}
 
@@ -256,7 +256,7 @@ static int netvsc_destroy_buf(struct hv_device *device)
 		if (ret != 0) {
 			netdev_err(ndev,
 				   "unable to teardown receive buffer's gpadl\n");
-			return ret;
+			return;
 		}
 		net_device->recv_buf_gpadl_handle = 0;
 	}
@@ -300,7 +300,7 @@ static int netvsc_destroy_buf(struct hv_device *device)
 		if (ret != 0) {
 			netdev_err(ndev, "unable to send "
 				   "revoke send buffer to netvsp\n");
-			return ret;
+			return;
 		}
 	}
 	/* Teardown the gpadl on the vsp end */
@@ -314,7 +314,7 @@ static int netvsc_destroy_buf(struct hv_device *device)
 		if (ret != 0) {
 			netdev_err(ndev,
 				   "unable to teardown send buffer's gpadl\n");
-			return ret;
+			return;
 		}
 		net_device->send_buf_gpadl_handle = 0;
 	}
@@ -324,8 +324,6 @@ static int netvsc_destroy_buf(struct hv_device *device)
 		net_device->send_buf = NULL;
 	}
 	kfree(net_device->send_section_map);
-
-	return ret;
 }
 
 static int netvsc_init_buf(struct hv_device *device)