Don't bake the string into the printf format, use a '%s' and pass the string as a parameter.

Change-Id: I47be05383637caaa81a93d19623ff39c47988df3
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/31429Tested-by: Ben Clayton <bclayton@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>