fix test case

Author: farzonl

clang/test/CodeGenHLSL/builtins/D3DCOLORtoUBYTE4.hlsl

@@ -5,7 +5,7 @@
 // CHECK-LABEL: D3DCOLORtoUBYTE4
 int4 test_D3DCOLORtoUBYTE4(float4 p1) {
   // CHECK: %[[SCALED:.*]] = fmul [[FMFLAGS:.*]][[FLOAT_TYPE:<4 x float>]] %{{.*}}, splat (float 0x406FE01000000000)
-  // CHECK: %[[CONVERTED:.*]] = fptoui [[FLOAT_TYPE]] %[[SCALED]] to [[INT_TYPE:<4 x i32>]]
+  // CHECK: %[[CONVERTED:.*]] = fptosi [[FLOAT_TYPE]] %[[SCALED]] to [[INT_TYPE:<4 x i32>]]
   // CHECK: %[[SHUFFLED:.*]] = shufflevector [[INT_TYPE]] %[[CONVERTED]], [[INT_TYPE]] poison, <4 x i32> <i32 2, i32 1, i32 0, i32 3>
   // CHECK: ret [[INT_TYPE]] %[[SHUFFLED]]
   return D3DCOLORtoUBYTE4(p1);