Perform query classifier initialization implicitly

The setting up and the initialization of the query classifier has
now been separated. The gateway explicitly sets up the query
classifier (i.e. chooses which one to use and what arguments to
provide), but the actual initialization is performed as part of
the general module initialization.

query_classifier/qc_mysqlembedded/qc_mysqlembedded.cc

@@ -2477,7 +2477,7 @@ void configure_options(const char* datadir, const char* langdir)
     server_options[IDX_DATADIR] = datadir_arg;
 
     rv = sprintf(language_arg, "--language=%s", langdir);
-    ss_dassert(rv < OPTIONS_LANGUAGE_SIZE); // Ensured by qc_init().
+    ss_dassert(rv < OPTIONS_LANGUAGE_SIZE); // Ensured by qc_process_init().
     server_options[IDX_LANGUAGE] = language_arg;
 
     // To prevent warning of unused variable when built in release mode,
@@ -2498,7 +2498,7 @@ bool qc_setup(const char* args)
     return true;
 }
 
-bool qc_init(void)
+int qc_mysql_process_init(void)
 {
     bool inited = false;
 
@@ -2530,15 +2530,15 @@ bool qc_init(void)
         }
     }
 
-    return inited;
+    return inited ? 0 : -1;
 }
 
-void qc_end(void)
+void qc_mysql_process_end(void)
 {
     mysql_library_end();
 }
 
-bool qc_thread_init(void)
+int qc_mysql_thread_init(void)
 {
     bool inited = (mysql_thread_init() == 0);
 
@@ -2547,10 +2547,10 @@ bool qc_thread_init(void)
         MXS_ERROR("mysql_thread_init() failed.");
     }
 
-    return inited;
+    return inited ? 0 : -1;
 }
 
-void qc_thread_end(void)
+void qc_mysql_thread_end(void)
 {
     mysql_thread_end();
 }
@@ -2567,10 +2567,10 @@ MXS_MODULE* MXS_CREATE_MODULE()
     static QUERY_CLASSIFIER qc =
     {
         qc_setup,
-        qc_init,
-        qc_end,
-        qc_thread_init,
-        qc_thread_end,
+        qc_mysql_process_init,
+        qc_mysql_process_end,
+        qc_mysql_thread_init,
+        qc_mysql_thread_end,
         qc_parse,
         qc_get_type,
         qc_get_operation,
@@ -2594,10 +2594,10 @@ MXS_MODULE* MXS_CREATE_MODULE()
         "Query classifier based upon MySQL Embedded",
         "V1.0.0",
         &qc,
-        NULL, /* Process init. */
-        NULL, /* Process finish. */
-        NULL, /* Thread init. */
-        NULL, /* Thread finish. */
+        qc_mysql_process_init,
+        qc_mysql_process_end,
+        qc_mysql_thread_init,
+        qc_mysql_thread_end,
         {
             {MXS_END_MODULE_PARAMS}
         }