(filesets-alist-get): Use `let' rather than `let*'.

(filesets-alist-get): Use `let' rather than `let*'.
(filesets-ormap, filesets-sort-case-sensitive-flag, filesets-remake-shortcut,
filesets-ingroup-collect-files): Fix typos in docstrings.
(filesets-data-get-name, filesets-data-get-data, filesets-data-set,
filesets-cmd-query-replace-getargs, filesets-ingroup-collect,
filesets-find-or-display-file): Doc fixes.