FruDevice: fix FRU 6-bit ASCII field decoding

Fix uninitialized variable in 6-bit ASCII Fru field decoder which can
cause wrong decoding of first 4 symbols group.

Signed-off-by: Andrei Kartashev <a.kartashev@yadro.com>
Change-Id: I82522c651344fd08e707fa6ffde0974d3b970d14
diff --git a/src/FruDevice.cpp b/src/FruDevice.cpp
index e1e95f8..93f114b 100644
--- a/src/FruDevice.cpp
+++ b/src/FruDevice.cpp
@@ -903,7 +903,7 @@
 
         case FRUDataEncoding::sixBitASCII:
         {
-            unsigned int accum;
+            unsigned int accum = 0;
             unsigned int accumBitLen = 0;
             value = std::string();
             for (i = 0; i < len; i++, iter++)