Libburnia plugin: Fix while loop in `brasero_libisofs_write_image_to_fd_thread()` (#685983)

In commit 1b8397ee [1]

        commit 1b8397ee
        Author: Philippe Rouquier <bonfire-app@wanadoo.fr>
        Date:   Tue Oct 5 10:10:17 2010 +0200

            Fix for #630651 [2] - Basero creating incomplete image (.ISO) files

distributed since Brasero 2.91.1

        $ git tag --contains 1b8397ee | sort | head -n 1
        BRASERO_2_91_1

a small bug was introduced by forgetting to substitude a command with a newly introduced variable in the loop condition. This broke the loop reading out the data to be written to the disc.

This small error had a huge impacted as writing images on the fly always failed, because only half of the image was written to the disc. Several bug reports exist for this problem and are most likely due to this problem [3][4][5].

Substituting this command with the variable fixes the problem reported in GNOME Bugzilla bug 685983 [6].

Creating this patch would not have been possible without the invaluable and quick observations and explanations of Thomas Schmitt from the libburnia project [7]. In the end Michael Biebl from the Debian project stepped up to look into this problem and bisected this problem to the above commit. Thomas Schmitt pointed out the error afterward. A big thanks to both of them and everybody else reporting errors and providing logs!

[1] http://git.gnome.org/browse/brasero/commit/?id=1b8397ee252df2d554682ca2d694d5937fbf6e39
[2] https://bugzilla.gnome.org/show_bug.cgi?id=630651
[3] http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=688229
[4] http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=594753
[5] https://bugs.launchpad.net/ubuntu/+source/brasero/+bug/780117
[6] https://bugzilla.gnome.org/show_bug.cgi?id=685983
[7] http://libburnia-project.org/



Signed-off-by: Colin Walters <walters@verbum.org>