ram: Move src_page_req* to RAMState

This are the last postcopy fields still at MigrationState.  Once there
Move MigrationSrcPageRequest to ram.c and remove MigrationState
parameters where appropiate.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
diff --git a/migration/migration.c b/migration/migration.c
index c1730a0..5918b21 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -109,7 +109,6 @@
     };
 
     if (!once) {
-        qemu_mutex_init(&current_migration.src_page_req_mutex);
         current_migration.parameters.tls_creds = g_strdup("");
         current_migration.parameters.tls_hostname = g_strdup("");
         once = true;
@@ -957,7 +956,7 @@
     qemu_bh_delete(s->cleanup_bh);
     s->cleanup_bh = NULL;
 
-    migration_page_queue_free(s);
+    migration_page_queue_free();
 
     if (s->to_dst_file) {
         trace_migrate_fd_cleanup();
@@ -1131,8 +1130,6 @@
 
     migrate_set_state(&s->state, MIGRATION_STATUS_NONE, MIGRATION_STATUS_SETUP);
 
-    QSIMPLEQ_INIT(&s->src_page_requests);
-
     s->total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
     return s;
 }