HLSL: fix invalid spir-v vector * scalar for float1

Missing check for float results in always emitting OpIMul even for float types
diff --git a/SPIRV/GlslangToSpv.cpp b/SPIRV/GlslangToSpv.cpp
index c58013b..3569001 100755
--- a/SPIRV/GlslangToSpv.cpp
+++ b/SPIRV/GlslangToSpv.cpp
@@ -4633,7 +4633,9 @@
             assert(builder.isScalar(right));
             needMatchingVectors = false;
             binOp = spv::OpVectorTimesScalar;
-        } else
+        } else if (isFloat)
+            binOp = spv::OpFMul;
+          else
             binOp = spv::OpIMul;
         break;
     case glslang::EOpVectorTimesMatrix: