skins2: fix file descriptor leak and missing error check
skins2: fix file descriptor leak and missing error check

(cherry picked from commit 01bf3662b1af1673cc5f6efbb355a698983a7651)
Signed-off-by: Erwan Tulou <e27b355b6a481153648f03262de342e9eb9e2807@videolan.org>

jomanmuk/vlc-2.2,jomanmuk/vlc-2.2,jomanmuk/vlc-2.2,jomanmuk/vlc-2.2,jomanmuk/vlc-2.2,jomanmuk/vlc-2.2,jomanmuk/vlc-2.2