Remove RandomGenerator destructor

Defining a destructor for the RandomGenerator would
throw an error when calling the copy constructor of
the class.

Change-Id: I1cff86cb75b2e252a52e3fbd03ecb08e7a11b519
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/66181
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: Ryan Harrison <rharrison@chromium.org>
Commit-Queue: Ryan Harrison <rharrison@chromium.org>

fuzzers/random_generator.h

@@ -33,8 +33,6 @@ class RandomGenerator {
   /// @param size - size of data buffer
   explicit RandomGenerator(const uint8_t* data, size_t size);
 
-  ~RandomGenerator() {}
-
   /// Get uint32_t value from uniform distribution.
   /// @param lower - lower bound of integer generated
   /// @param upper - upper bound of integer generated