Steve Dibb authored Feb 17, 2014 and Jean-Baptiste Kempf committed Feb 18, 2014

In dvd_reader.c, the DVDDiscID function gets the MD5 from the total contents
of the IFO files on the disc.  However, it gets it by looping through the
the first ten IFO files, whether they exist or not.

This results in spewage, where a disc has less than ten.  In this case,
Dragonheart only has two:

libdvdnav:DVDOpenFileUDF:UDFFindFile /VIDEO_TS/VTS_03_0.IFO failed
libdvdnav:DVDOpenFileUDF:UDFFindFile /VIDEO_TS/VTS_04_0.IFO failed
libdvdnav:DVDOpenFileUDF:UDFFindFile /VIDEO_TS/VTS_05_0.IFO failed
libdvdnav:DVDOpenFileUDF:UDFFindFile /VIDEO_TS/VTS_06_0.IFO failed
libdvdnav:DVDOpenFileUDF:UDFFindFile /VIDEO_TS/VTS_07_0.IFO failed
libdvdnav:DVDOpenFileUDF:UDFFindFile /VIDEO_TS/VTS_08_0.IFO failed
libdvdnav:DVDOpenFileUDF:UDFFindFile /VIDEO_TS/VTS_09_0.IFO failed

Instead of using a set limit of 10 IFOs, this patch counts the number of
VTSes existing on the DVD, and will use that number instead if it is less
than 10.

Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>