tools: fix emacs configuration file

[rzalamena]

Summary

It was missing a set of parentheses and a dot before `indent-tabs-mode'.

More information here:
https://www.gnu.org/software/emacs/manual/html_node/emacs/Directory-Variables.html#Directory-Variables

Extra

I also have a extra configuration for flycheck:

((c-mode . (
            ;; Add path to `lib' and `config.h' so flycheck can find them
            ;; (include path are relative to the open file).
            (flycheck-gcc-include-path . ("." "../" "../lib"))
            (flycheck-clang-include-path . ("." "../" "../lib"))
            ;; Tell the compiler about the makefile guards.
            (flycheck-gcc-args . ("-std=gnu11"
                                  "-DHAVE_CONFIG_H"
                                  "-Wall"
                                  "-Wextra"
                                  "-Wstrict-prototypes"
                                  "-Wmissing-prototypes"
                                  "-Wmissing-declarations"
                                  "-Wshadow"
                                  "-Wpointer-arith"
                                  "-Wconversion"
                                  "-Wpacked"
                                  "-Wswitch-enum"
                                  "-Wimplicit-fallthrough"
                                  "-Wsuggest-attribute=const"
                                  "-Wsuggest-attribute=malloc"
                                  "-Walloc-zero"))
            (flycheck-clang-args . ("-std=gnu11"
                                    "-DHAVE_CONFIG_H"
                                    "-Wall"
                                    "-Wextra"
                                    "-Wstrict-prototypes"
                                    "-Wmissing-prototypes"
                                    "-Wmissing-declarations"
                                    "-Wshadow"
                                    "-Wpointer-arith"
                                    "-Wconversion"
                                    "-Wpacked"
                                    "-Wswitch-enum"
                                    "-Wimplicit-fallthrough"
                                    "-Wsuggest-attribute=const"
                                    "-Wsuggest-attribute=malloc"
                                    "-Walloc-zero"))
            )))

The snippet above can be added to .dir-locals.el or to .dir-locals-2.el (if using recent emacs version) to enable more flycheck warnings. flycheck can be found as a package in emacs melpa repositories and you'll also need flycheck-clang-analyzer for the clang compiler.

NOTE: emacs will warn/ask you about the flycheck variables since you could theoretically pass malicious arguments.

[LabN-CI]

💚 Basic BGPD CI results: SUCCESS, 0 tests failed

Results table

_	_
Result	SUCCESS git merge/5275 3a0f661
Date	11/04/2019
Start	10:32:06
Finish	10:53:50
Run-Time	21:44
Total	1815
Pass	1815
Fail	0
Valgrind-Errors	0
Valgrind-Loss	0
Details	vncregress-2019-11-04-10:32:06.txt
Log	autoscript-2019-11-04-10:32:59.log.bz2
Memory	436 425 360

For details, please contact louberger

[NetDEF-CI]

Continuous Integration Result: SUCCESSFUL

Congratulations, this patch passed basic tests

Tested-by: NetDEF / OpenSourceRouting.org CI System

CI System Testrun URL: https://ci1.netdef.org/browse/FRR-FRRPULLREQ-9589/

This is a comment from an automated CI system.
For questions and feedback in regards to this CI system, please feel free to email
Martin Winter - mwinter (at) opensourcerouting.org.