avformat/mxfdec: Fix termination of mxf_data_essence_container_uls

Fixes: asan_static-oob_87d116_10_201.mxf
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avformat/mxfdec: Fix memleak of primer_packs

Fixes: asan_static-oob_87d116_10_201.mxf
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avformat/mxfdec: Fix memleak of packages_refs

Fixes: asan_static-oob_87d116_10_201.mxf
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avformat/mxfdec: cleanup if parsing the header metadata fails

Fixes memleaks
Fixes: asan_static-oob_87d116_10_201.mxf
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>