Eliminate warning messages from test-attention.cpp file

Signed-off-by: austinfcui <austinfcui@gmail.com>
Change-Id: Ib933179c8d11486333bfb60a477a3a47dfc7e685
diff --git a/test/test-attention.cpp b/test/test-attention.cpp
index ec92089..0cda941 100644
--- a/test/test-attention.cpp
+++ b/test/test-attention.cpp
@@ -69,7 +69,7 @@
     }
 
     std::unique_ptr<Attention> pAttn;
-    Config* config;
+    Config* config      = nullptr;
     pdbg_target* target = nullptr;
 };
 
@@ -140,7 +140,7 @@
     }
 
     std::unique_ptr<Attention> pAttn;
-    Config* config;
+    Config* config      = nullptr;
     pdbg_target* target = nullptr;
     uint32_t attr;
 };