Attn: Code cleanup based on CI build suggestions

Lessened the scope of some variables, made explicit a constructor,
changed a variable name that was shadowing a function name, removed some
unused code.

Signed-off-by: Ben Tyner <ben.tyner@ibm.com>
Change-Id: I430f6dece8b606318a0ffa476bf06f9a0060f72d
diff --git a/attn/pel/pel_minimal.hpp b/attn/pel/pel_minimal.hpp
index cde0ead..79c0c11 100644
--- a/attn/pel/pel_minimal.hpp
+++ b/attn/pel/pel_minimal.hpp
@@ -46,7 +46,7 @@
      *
      * @param[in] pelBuffer - buffer containing a raw PEL
      */
-    PelMinimal(std::vector<uint8_t>& data);
+    explicit PelMinimal(std::vector<uint8_t>& data);
 
     /**
      * @brief Stream raw PEL data to buffer