When launching QEMU with "-loadvm", usbredir_create_parser() should avoid
setting up the hello packet (just as with "-incoming". On the latest version
of libusbredir, usbredirparser_unserialize() will return error if the parser
is not "pristine."

Signed-off-by: Joelle van Dyne <j@getutm.app>
Message-Id: <20220507041850.98716-1-j@getutm.app>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>