Fix DebugColorPicker warning

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Debug/DebugDisplay.hlsl

     }
 
     // 4. Display leading 0
-#pragma warning(disable : 3557) // loop only executes for 0 iteration(s)
-    for (int i = 0; i < leading0; ++i)
+    if (leading0 > 0)
-        DrawCharacter('0', fontColor, currentUnormCoord, fixedUnormCoord, flipY, color, -1);
+        for (int i = 0; i < leading0; ++i)
+        {
+            DrawCharacter('0', fontColor, currentUnormCoord, fixedUnormCoord, flipY, color, -1);
+        }
-#pragma warning(default : 3557)
 
     // 5. Display sign
     if (intValue < 0 || forceNegativeSign)