gda: fix getmem_nbi_wg source and dest (#311)

A copy paste mistake in a previous commit caused source and dest to
be reversed.  Correct the source and dest params.

Fixes: 6de67d5d7c

Signed-off-by: Allen Hubbe <allen.hubbe@amd.com>

src/gda/context_gda_device.cpp

@@ -214,7 +214,7 @@ __device__ void GDAContext::getmem_nbi_wg(void *dest, const void *source,
   }
   uint64_t L_offset = const_cast<char *>(src_typed) - base_heap[my_pe];
   if (is_wave_zero_in_block()) {
-    qps[pe].get_nbi(base_heap[pe] + L_offset, source, nelems, pe, QueuePair::WAVE);
+    qps[pe].get_nbi(dest, base_heap[pe] + L_offset, nelems, pe, QueuePair::WAVE);
   }
 }