Minor style fixes and improvements for gpio code.
diff --git a/bbb_cape/src/bbb/gpi.cc b/bbb_cape/src/bbb/gpi.cc
index 9045eca..90c46d5 100644
--- a/bbb_cape/src/bbb/gpi.cc
+++ b/bbb_cape/src/bbb/gpi.cc
@@ -45,4 +45,4 @@
   return atoi(&buf);
 }
 
-} // namespace bbb
+}  // namespace bbb