initialize responseBuffer array

More testing did not like the array not being explicitly filled ahead of
use.

Signed-off-by: Patrick Venture <venture@google.com>
Change-Id: Ibefcf7d8bb141d073fa453b8f804d91582555f00
diff --git a/src/ipmiblob/ipmi_handler.cpp b/src/ipmiblob/ipmi_handler.cpp
index 39dc3aa..0d7c44e 100644
--- a/src/ipmiblob/ipmi_handler.cpp
+++ b/src/ipmiblob/ipmi_handler.cpp
@@ -80,7 +80,7 @@
     constexpr int ipmiOk = 0;
 
     /* We have a handle to the IPMI device. */
-    std::array<std::uint8_t, ipmiResponseBufferLen> responseBuffer;
+    std::array<std::uint8_t, ipmiResponseBufferLen> responseBuffer = {};
 
     /* Build address. */
     ipmi_system_interface_addr systemAddress{};