loader: GH362 - Fix json output of escape chars
loader: GH362 - Fix json output of escape chars

The strings from the JSON file already add escape characters.
So, \ becomes \\ in the JSON file strings.  However, the cJSON
library was adding \\ for ever encountered \ when converting
to a string.  This became messy as C:\\vulkanSDK\\layerfile.json
became C:\\\\vulkanSDK\\\\layerfile.json.

Change-Id: I006252e33d6e91e2bef704dd5dee0777105388a7

KhronosGroup/Vulkan-LoaderAndValidationLayers,KhronosGroup/Vulkan-LoaderAndValidationLayers,KhronosGroup/Vulkan-LoaderAndValidationLayers,elongbug/Vulkan-LoaderAndValidationLayers,elongbug/Vulkan-LoaderAndValidationLayers,KhronosGroup/Vulkan-LoaderAndValidationLayers,elongbug/Vulkan-LoaderAndValidationLayers,elongbug/Vulkan-LoaderAndValidationLayers