Commit 3e0c54bf4d touches 'configure.ac' which
in turn regenerates 'po/Makefile.in.in' with the wrong SHELL and breaks
install. While at it, consolidate the other patching phases and remove
unneeded inputs.
* gnu/packages/video.scm (vlc)[arguments]: Consolidate patching phases into a
'patch-source' phase and run it immediately after unpack.
[native-inputs]: Remove AUTOCONF, AUTOMAKE and LIBTOOL.