mountlist: Merge two .m4 files. * m4/mountlist.m4 (gl_MOUNTLIST): Inline gl_LIST_MOUNTED_FILE_SYSTEMS. (AC_FUNC_GETMNTENT): Move to here, from m4/ls-mntd-fs.m4. * m4/ls-mntd-fs.m4: Remove file. * modules/mountlist (Files): Remove m4/ls-mntd-fs.m4.