message: remove useless example in ISPC usage
diff: @@ -109,11 +109,9 @@ The following are concerns specific to ISPC:
  but uniform values are more efficient than replicated varying values.
  - Avoid writing unnecessary `uniform` and `varying` keywords. Examples:
  ```cpp
  -varying float a; // 'varying' is redundant, variables are varying by default
  +varying float; // 'varying' is redundant, variables are varying by default
  uniform float *; // 'uniform' is redundant, pointers point to uniform by default
  -
  -varying void *; // `varying` is meaningless, void has no varyingness to it
  ```
  - Prefer omitting `uniform`/`varying` qualifiers for structs. Only apply them
  if they need to be consistenly the same for both `uniform` and `varying`
  