[rocm-libraries] ROCm/rocm-libraries#6233 (commit a9a0519)

Fix memory leaks in rocRAND and hipRAND

## Motivation

Fixing memory leaks is good.

## Technical Details

Fixed assorted memory leaks in the rocRAND/hipRAND unit tests, and one
memory leak in mtgp32.hpp - the test code showed a pattern which could
cause rocRAND's mtgp32_generator_template to not free m_engines.

## Test Plan

Run unit tests to verify nothing is broken and leaks are gone.

## Test Result

Memory leaks no longer reported by ASAN.

## Submission Checklist

- [ ] Look over the contributing guidelines at
https://github.com/ROCm/ROCm/blob/develop/CONTRIBUTING.md#pull-requests.

Author: stanleytsang-amd

library/src/rng/mtgp32.hpp

@@ -80,7 +80,8 @@ namespace rocrand_impl::host
 struct mtgp32_device_engine : ::rocrand_device::mtgp32_engine
 {
     // suppress warning about no initialization for __shared__ variables
-    __host__ __device__ mtgp32_device_engine(){};
+    __host__ __device__
+    mtgp32_device_engine() {};
 
     __forceinline__ __host__ __device__
     unsigned int next()
@@ -366,7 +367,7 @@ class mtgp32_generator_template : public generator_impl_base
         return *this;
     }
 
-    ~mtgp32_generator_template()
+    void free_engines()
     {
         if(m_engines != nullptr)
         {
@@ -375,13 +376,19 @@ class mtgp32_generator_template : public generator_impl_base
         }
     }
 
+    ~mtgp32_generator_template()
+    {
+        free_engines();
+    }
+
     static constexpr rocrand_rng_type type()
     {
         return ROCRAND_RNG_PSEUDO_MTGP32;
     }
 
     void reset() override final
     {
+        free_engines();
         m_engines_initialized = false;
     }