Use s.c_str() in log messages

Partly resolves openbmc/openbmc 2905

Tested: static_assert only

Change-Id: Ib22b2cd079422cd0de806d22302099c3f1a09887
Signed-off-by: Joseph Reynolds <jrey@us.ibm.com>
diff --git a/host-interface.cpp b/host-interface.cpp
index f32db3f..e00e07f 100644
--- a/host-interface.cpp
+++ b/host-interface.cpp
@@ -36,7 +36,7 @@
 
     log<level::INFO>("Pushing cmd on to queue",
             entry("CONTROL_HOST_CMD=%s",
-                  convertForMessage(command)));
+                  convertForMessage(command).c_str()));
 
     // If the command is OCCReset, then all we need is just sensor ID
     // This is the only command that is being used now.