Add definitions of MXS_MODULE_NAME to all modules

All modules now declare a name for the module. This is name is added as a
prefix to all messages logged by a module. The prefix should help
determine which part of the system logs a message.

server/modules/authenticator/GSSAPI/GSSAPIAuth/gssapi_auth.c

@@ -11,6 +11,8 @@
  * Public License.
  */
 
+#define MXS_MODULE_NAME "GSSAPIAuth"
+
 #include <maxscale/gw_authenticator.h>
 #include <maxscale/alloc.h>
 #include <maxscale/dcb.h>

server/modules/authenticator/GSSAPI/GSSAPIBackendAuth/gssapi_backend_auth.c

@@ -11,6 +11,8 @@
  * Public License.
  */
 
+#define MXS_MODULE_NAME "GSSAPIBackendAuth"
+
 #include <maxscale/gw_authenticator.h>
 #include <maxscale/alloc.h>
 #include <maxscale/dcb.h>