maint.mk: _sc_search_regexp: generalize and rename from _prohibit_regexp

maint.mk: _sc_search_regexp: generalize and rename from _prohibit_regexp

Adapt existing rules to use the new factorization, which provides
a more declarative syntax for pattern searching syntax checks.
* top/maint.mk (_sc_search_regexp): Rename from _prohibit_regexp.
(sc_cast_of_argument_to_free): Adapt to use _sc_search_regexp.
(sc_cast_of_x_alloc_return_value): Likewise.
(sc_cast_of_alloca_return_value): Likewise.
(sc_space_tab): Likewise.
(sc_prohibit_atoi_atof): Likewise.
(sc_prohibit_magic_number_exit): Likewise.
(sc_error_exit_success): Likewise.
(sc_file_system): Likewise.
(sc_prohibit_have_config_h): Likewise.
(sc_require_config_h): Likewise.
(sc_prohibit_HAVE_MBRTOWC): Likewise.
(sc_obsolete_symbols): Likewise.
(sc_changelog): Likewise.
(sc_program_name): Likewise.
(sc_the_the): Likewise.
(sc_trailing_blank): Likewise.
(sc_two_space_separator_in_usage): Likewise.
(sc_useless_cpp_parens): Likewise.
(sc_GPL_version): Likewise.
(sc_GFDL_version): Likewise.
(sc_texinfo_acronym): Likewise.
(sc_prohibit_cvs_keyword): Likewise.
(sc_prohibit_stat_st_blocks): Likewise.
(sc_prohibit_S_IS_definition): Likewise.
(sc_redundant_const): Likewise.
(sc_makefile_TAB_only_indentation): Likewise.
(sc_m4_quote_check): Likewise.
(sc_makefile_path_separator_check): Likewise.
(sc_copyright_check): Likewise.
(sc_Wundef_boolean): Likewise.
(sc_vulnerable_makefile_CVE-2009-4029): Likewise.