Attn: Fix CI complaint of unused-results

Use the results provided by file read/write operations. For mismatch in
number of bytes written on ffdc data creation we add a trace message,
for mismatch in number of bytes read during pel creation we skip
creating the pel.

Signed-off-by: Ben Tyner <ben.tyner@ibm.com>
Change-Id: I3ec6755ef258ac869775b08afafae324a76a2884
diff --git a/attn/attn_logging.hpp b/attn/attn_logging.hpp
index 7e89555..4f1f785 100644
--- a/attn/attn_logging.hpp
+++ b/attn/attn_logging.hpp
@@ -17,7 +17,8 @@
 /** @brief Logging level types */
 enum level
 {
-    INFO
+    INFO,
+    ERROR
 };
 
 /** @brief Logging event types */