vktrace : Fix Visual Studio 2015 build.
vktrace : Fix Visual Studio 2015 build.

It didn't like the " from the literal string being immediatelly
followed by the " contained in the VK_SIZE_T_SPECIFIER define.

Change-Id: I0c4641d7a488d3d854496c48eb3b108c84150233

sashinde/VulkanTools,sashinde/VulkanTools,sashinde/VulkanTools,sashinde/VulkanTools