rusticl/api: protect against 0 length in slice::from_raw_parts

Fixes: 84d16045d0 ("rusticl/api: add param to query which contains application provided values")
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/30410>

src/gallium/frontends/rusticl/api/util.rs

@@ -26,7 +26,7 @@ pub trait CLInfo<I> {
         param_value: *mut ::std::os::raw::c_void,
         param_value_size_ret: *mut usize,
     ) -> CLResult<()> {
-        let arr = if !param_value.is_null() {
+        let arr = if !param_value.is_null() && param_value_size != 0 {
             unsafe { slice::from_raw_parts(param_value.cast(), param_value_size) }
         } else {
             &[]