Add missing hipEventDestroy calls in tests to solve mem leak (#580)

Author: evedovelli

test/common.hpp

@@ -664,6 +664,8 @@ namespace rocwmma
         CHECK_HIP_ERROR(
             hipMemcpy(&maxRelativeError, d_relativeError, sizeof(double), hipMemcpyDeviceToHost));
 
+        CHECK_HIP_ERROR(hipEventDestroy(syncEvent));
+
         // Free allocated device memory
         CHECK_HIP_ERROR(hipFree(d_relativeError));
 
@@ -745,6 +747,8 @@ namespace rocwmma
         CHECK_HIP_ERROR(
             hipMemcpy(&maxRelativeError, d_relativeError, sizeof(double), hipMemcpyDeviceToHost));
 
+        CHECK_HIP_ERROR(hipEventDestroy(syncEvent));
+
         // Free allocated device memory
         CHECK_HIP_ERROR(hipFree(d_relativeError));