Use s.c_str() in log messages

Part of a series of commits that resolve openbmc 2905

Here is something funny: in item_updater.cpp:300 is a string
and on line 316 it is const char*.   It may be confusing to
have the same variable name with two different related types.

Tested: static_assert only

Change-Id: I59556fc184ef1f1047bd8a76062598b7518c36ae
Signed-off-by: Joseph Reynolds <jrey@us.ibm.com>
diff --git a/activation.cpp b/activation.cpp
index 87e5d2b..11c7b32 100755
--- a/activation.cpp
+++ b/activation.cpp
@@ -205,7 +205,7 @@
     if (mapperResponseMsg.is_method_error())
     {
         log<level::ERR>("Error in Get Delete Object",
-                        entry("VERSIONPATH=%s", path));
+                        entry("VERSIONPATH=%s", path.c_str()));
         return;
     }
     std::map<std::string, std::vector<std::string>> mapperResponse;
@@ -213,7 +213,7 @@
     if (mapperResponse.begin() == mapperResponse.end())
     {
         log<level::ERR>("ERROR in reading the mapper response",
-                        entry("VERSIONPATH=%s", path));
+                        entry("VERSIONPATH=%s", path.c_str()));
         return;
     }
 
@@ -227,7 +227,7 @@
     if (mapperResponseMsg.is_method_error())
     {
         log<level::ERR>("Error in Deleting image from image manager",
-                        entry("VERSIONPATH=%s", path));
+                        entry("VERSIONPATH=%s", path.c_str()));
         return;
     }
 }