Revert "block: Remove dead deprecation warning code"

This reverts commit 6266e900.

Some deprecated -drive options were still in use by libvirt, only
fixed with libvirt commit b340c6c614 ("qemu: format serial and geometry
on frontend disk device"), which is not yet in any released version
of libvirt.

So let's hold off removing the deprecated options for one more QEMU
release.
Reported-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NCornelia Huck <cohuck@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

blockdev.c

@@ -775,6 +775,8 @@ DriveInfo *drive_new(QemuOpts *all_opts, BlockInterfaceType block_default_type)
     const char *filename;
     Error *local_err = NULL;
     int i;
+    const char *deprecated[] = {
+    };
 
     /* Change legacy command line options into QMP ones */
     static const struct {
@@ -851,6 +853,16 @@ DriveInfo *drive_new(QemuOpts *all_opts, BlockInterfaceType block_default_type)
         goto fail;
     }
 
+    /* Other deprecated options */
+    if (!qtest_enabled()) {
+        for (i = 0; i < ARRAY_SIZE(deprecated); i++) {
+            if (qemu_opt_get(legacy_opts, deprecated[i]) != NULL) {
+                error_report("'%s' is deprecated, please use the corresponding "
+                             "option of '-device' instead", deprecated[i]);
+            }
+        }
+    }
+
     /* Media type */
     value = qemu_opt_get(legacy_opts, "media");
     if (value) {