rename header: fru-area.hpp to fru_area.hpp

Rename fru-area.hpp header file per the openbmc file naming convention.

Change-Id: I751c8d5650bb5e71238923c4728a9cdedccc7c7f
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/writefrudata.cpp b/writefrudata.cpp
index a53859b..0294e57 100644
--- a/writefrudata.cpp
+++ b/writefrudata.cpp
@@ -1,6 +1,6 @@
 #include "writefrudata.hpp"
 
-#include "fru-area.hpp"
+#include "fru_area.hpp"
 #include "frup.hpp"
 #include "types.hpp"