Updating link for C SDKs (device and service)

Both device and service SDK install links were pointing to the device specific content. Instead we may want to have both point to the root content for C the SDKs.

Author: wickste

articles/iot-hub/iot-hub-devguide-sdks.md

@@ -139,7 +139,7 @@ Other reference topics in this IoT Hub developer guide include:
 [lnk-npm-service]: https://www.npmjs.com/package/azure-iothub
 [lnk-nuget-csharp-device]: https://www.nuget.org/packages/Microsoft.Azure.Devices.Client/
 [lnk-nuget-csharp-service]: https://www.nuget.org/packages/Microsoft.Azure.Devices/
-[lnk-c-package]: https://github.com/Azure/azure-iot-sdk-c/blob/master/iothub_client/readme.md
+[lnk-c-package]: https://github.com/Azure/azure-iot-sdk-c/blob/master/readme.md
 [lnk-pip-device]: https://pypi.python.org/pypi/azure-iothub-device-client/
 [lnk-pip-service]: https://pypi.python.org/pypi/azure-iothub-service-client/
 
@@ -151,4 +151,4 @@ Other reference topics in this IoT Hub developer guide include:
 [lnk-benefits-blog]: https://azure.microsoft.com/blog/benefits-of-using-the-azure-iot-sdks-in-your-azure-iot-solution/
 [lnk-cocoa-device]: https://cocoapods.org/pods/AzureIoTHubClient
 [lnk-ios-sample]: https://github.com/Azure-Samples/azure-iot-samples-ios
-[lnk-cocoa-service]: https://cocoapods.org/pods/AzureIoTHubServiceClient
+[lnk-cocoa-service]: https://cocoapods.org/pods/AzureIoTHubServiceClient