gnu: cvs: Rename patch file.

* gnu/packages/version-control.scm (cvs)[source]: Rename patch.
* gnu/packages/patches/cvs-2017-12836.patch: Rename to ...
* gnu/packages/patches/cvs-CVE-2018-12836.patch: ... this.
* gnu/local.mk (dist_patch_DATA): Register it.

gnu/local.mk

@@ -747,7 +747,7 @@ dist_patch_DATA =						\
   %D%/packages/patches/clucene-contribs-lib.patch               \
   %D%/packages/patches/cube-nocheck.patch			\
   %D%/packages/patches/cursynth-wave-rand.patch			\
-  %D%/packages/patches/cvs-2017-12836.patch			\
+  %D%/packages/patches/cvs-CVE-2017-12836.patch		\
   %D%/packages/patches/dbus-helper-search-path.patch		\
   %D%/packages/patches/dbus-CVE-2019-12749.patch		\
   %D%/packages/patches/dealii-mpi-deprecations.patch		\

gnu/packages/version-control.scm

@@ -1409,7 +1409,7 @@ (define-public cvs
              (uri (string-append
                    "https://ftp.gnu.org/non-gnu/cvs/source/feature/"
                    version "/cvs-" version ".tar.bz2"))
-             (patches (search-patches "cvs-2017-12836.patch"))
+             (patches (search-patches "cvs-CVE-2017-12836.patch"))
              (sha256
               (base32
                "0pjir8cwn0087mxszzbsi1gyfc6373vif96cw4q3m1x6p49kd1bq"))))