[plugins] Force write of user-space buffered data to output
[plugins] Force write of user-space buffered data to output

hughsie/libhif,rpm-software-management/libhif,Conan-Kudo/libhif,rpm-software-management/libdnf,Conan-Kudo/libhif,rpm-software-management/libdnf,rpm-software-management/libhif,rpm-software-management/libdnf,rpm-software-management/libdnf,rpm-software-management/libhif,rpm-software-management/libhif,hughsie/libhif,Conan-Kudo/libhif,hughsie/libhif,hughsie/libhif,Conan-Kudo/libhif