Fix benchmarks to wait on correct event (#477)

Wait on the relevant event or vector of events for the operator 
rather than waiting for all the events in the queue.

Author: pgorlani

benchmark/portblas/blas2/ger.cpp

@@ -105,7 +105,7 @@ void run(benchmark::State& state, blas::SB_Handle* sb_handle_ptr, index_t m,
   auto blas_method_def = [&]() -> std::vector<cl::sycl::event> {
     auto event = _ger(sb_handle, m, n, alpha, v_x_gpu, incX, v_y_gpu, incY,
                       m_a_gpu, lda);
-    sb_handle.wait();
+    sb_handle.wait(event);
     return event;
   };
 

benchmark/portblas/blas2/symv.cpp

@@ -105,7 +105,7 @@ void run(benchmark::State& state, blas::SB_Handle* sb_handle_ptr,
   auto blas_method_def = [&]() -> std::vector<cl::sycl::event> {
     auto event = _symv(sb_handle, *uplo_str, n, alpha, m_a_gpu, lda, v_x_gpu,
                        incX, beta, v_y_gpu, incY);
-    sb_handle.wait();
+    sb_handle.wait(event);
     return event;
   };
 

benchmark/portblas/blas2/syr.cpp

@@ -96,7 +96,7 @@ void run(benchmark::State& state, blas::SB_Handle* sb_handle_ptr,
   auto blas_method_def = [&]() -> std::vector<cl::sycl::event> {
     auto event =
         _syr(sb_handle, *uplo_str, n, alpha, v_x_gpu, incX, m_a_gpu, lda);
-    sb_handle.wait();
+    sb_handle.wait(event);
     return event;
   };
 

benchmark/portblas/blas2/syr2.cpp

@@ -106,7 +106,7 @@ void run(benchmark::State& state, blas::SB_Handle* sb_handle_ptr,
   auto blas_method_def = [&]() -> std::vector<cl::sycl::event> {
     auto event = _syr2(sb_handle, *uplo_str, n, alpha, v_x_gpu, incX, v_y_gpu,
                        incY, m_a_gpu, lda);
-    sb_handle.wait();
+    sb_handle.wait(event);
     return event;
   };
 

benchmark/portblas/blas2/trmv.cpp

@@ -99,7 +99,7 @@ void run(benchmark::State& state, blas::SB_Handle* sb_handle_ptr,
   auto blas_method_def = [&]() -> std::vector<cl::sycl::event> {
     auto event = _trmv(sb_handle, *uplo_str, *t_str, *diag_str, n, m_a_gpu, lda,
                        v_x_gpu, incX);
-    sb_handle.wait();
+    sb_handle.wait(event);
     return event;
   };