(customize): Fix typo in error message.

(customize): Fix typo in error message.
(verilog-mode, verilog-mode-indent, verilog-mode-actions, verilog-mode-auto,
verilog-indent-level-module, verilog-minimum-comment-distance,
verilog-library-flags, verilog-library-directories, verilog-library-files,
verilog-auto-reset-widths, verilog-imenu-generic-expression,
verilog-xemacs-menu, verilog-set-compile-command, verilog-set-compile-command,
verilog-mode-syntax-table, verilog-mode, verilog-get-expr,
verilog-strip-comments, verilog-one-line, verilog-lint-off, verilog-batch-auto,
verilog-batch-delete-auto, verilog-batch-inject-auto, verilog-batch-indent,
verilog-continued-line, verilog-type-keywords, verilog-read-sub-decls-sig,
verilog-read-sub-decls-line, verilog-read-inst-pins, verilog-read-arg-pins,
verilog-read-auto-template, verilog-read-signals, verilog-getopt-file,
verilog-add-list-unique, verilog-symbol-detick, verilog-modi-filename,
verilog-auto-star, verilog-auto-inst, verilog-auto-wire, verilog-enum-ascii,
verilog-sk-begin, verilog-sk-fork, verilog-sk-datadef,
verilog-colorize-include-files-buffer): Fix typos in docstrings.
(verilog-set-auto-endcomments, verilog-calculate-indent, verilog-inject-auto,
verilog-auto-arg, verilog-auto-inout-module): Reflow docstrings.
(verilog-tab-always-indent, verilog-highlight-p1800-keywords,
verilog-auto-star-save, verilog-auto-inst-vector, verilog-mode-hook,
electric-verilog-forward-sexp, verilog-in-case-region-p,
verilog-in-struct-region-p, verilog-in-generate-region-p, verilog-leap-to-head,
verilog-current-indent-level, verilog-case-indent-level, verilog-cpp-keywords,
verilog-defun-keywords, verilog-block-keywords, verilog-tf-keywords,
verilog-case-keywords, verilog-separator-keywords, verilog-completion,
verilog-signals-not-in, verilog-symbol-detick-text,
verilog-modi-cache-preserve-tick, verilog-modi-cache-preserve-buffer,
verilog-forward-close-paren, verilog-backward-open-paren,
verilog-backward-open-bracket): Doc fixes.