migration: remove check against colo support

Since commit a15215f3 ("build: remove --enable-colo/--disable-colo"),
colo is always supported. We don't need any colo_supported() now since
it is always true. Removing any extra code that depends on it.

CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Hailiang Zhang <zhang.zhanghailiang@huawei.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Zhang Chen<zhangchen.fnst@cn.fujitsu.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <1500349150-13240-8-git-send-email-peterx@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

include/migration/colo.h

@@ -15,7 +15,6 @@
 
 #include "qemu-common.h"
 
-bool colo_supported(void);
 void colo_info_init(void);
 
 void migrate_start_colo_process(MigrationState *s);

migration/colo.c

@@ -29,11 +29,6 @@ static bool vmstate_loading;
 
 #define COLO_BUFFER_BASE_SIZE (4 * 1024 * 1024)
 
-bool colo_supported(void)
-{
-    return true;
-}
-
 bool migration_in_colo_state(void)
 {
     MigrationState *s = migrate_get_current();

migration/migration.c

@@ -412,9 +412,6 @@ MigrationCapabilityStatusList *qmp_query_migrate_capabilities(Error **errp)
             continue;
         }
 #endif
-        if (i == MIGRATION_CAPABILITY_X_COLO && !colo_supported()) {
-            continue;
-        }
         if (head == NULL) {
             head = g_malloc0(sizeof(*caps));
             caps = head;
@@ -613,14 +610,6 @@ void qmp_migrate_set_capabilities(MigrationCapabilityStatusList *params,
             continue;
         }
 #endif
-        if (cap->value->capability == MIGRATION_CAPABILITY_X_COLO) {
-            if (!colo_supported()) {
-                error_setg(errp, "COLO is not currently supported, please"
-                             " configure with --enable-colo option in order to"
-                             " support COLO feature");
-                continue;
-            }
-        }
         s->enabled_capabilities[cap->value->capability] = cap->value->state;
     }