shader_jit: Fix non-SSE4.1 path where FLR would not truncate

src/video_core/shader/shader_jit_x64.cpp

@@ -491,7 +491,7 @@ void JitShader::Compile_FLR(Instruction instr) {
     if (Common::GetCPUCaps().sse4_1) {
         ROUNDFLOORPS(SRC1, R(SRC1));
     } else {
-        CVTPS2DQ(SRC1, R(SRC1));
+        CVTTPS2DQ(SRC1, R(SRC1));
         CVTDQ2PS(SRC1, R(SRC1));
     }