* gnu/packages/pdf.scm (mupdf)[source]: Drop patch and part of snippet
  modifying permissions of files added by the patch.
  [arguments]: Use #:make-flags instead of modified build and install phases.
  Drop superfluous module inclusion. Use modify-phases syntax.
* gnu/packages/patches/mupdf-buildsystem-fix.patch: Remove patch.
* gnu-system.am (dist_patch_DATA): Unregister patch.