vulkaninfo: Fix issue 202

vulkaninfo: Fix issue 202

Vulkaninfo was replacing function `snprintf`
with function `_snprintf` on windows.

This seems to be for backwards compatiblity
with VS2013.

`_snprintf` is considered deprecated in VS2015
as `snprintf` is properly implemented.

Since we are dropping compatibility with VS2013 it
seems like this replacement should be removed.

Due to AppVeyor failing to build when this pre-processor
command is removed entirely, the command has been modified
to replace `snprintf` with `_snprintf_s`.

This command should hopefully be removed entirely in a future
commit.

Change-Id: I85f726fcb0a1cfcc902487100d35dc63d2ba00d8