(flymake-create-temp-with-folder-structure): Use expand-file-name.

(flymake-create-temp-with-folder-structure): Use expand-file-name.
(flymake-delete-temp-directory): Use expand-file-name,
file-name-directory, and directory-file-name.
(flymake-strrchr): Delete.
(flymake-start-syntax-check): Don't pass the redundant buffer argument
to the init-f function.
(flymake-init-find-buildfile-dir, flymake-init-create-temp-buffer-copy)
(flymake-init-create-temp-source-and-master-buffer-copy, flymake-perl-init)
(flymake-save-buffer-in-file, flymake-simple-make-init-impl, flymake-xml-init)
(flymake-simple-make-init, flymake-master-make-init, flymake-master-tex-init)
(flymake-master-make-header-init, flymake-simple-make-java-init)
(flymake-simple-ant-java-init, flymake-simple-tex-init):
Remove corresponding redundant buffer argument.
(flymake-allowed-file-name-masks): Remove last elems that are equal to
the default anyway.  Clean up regexps.