gnu: subversion, cmake: Clean up descriptions.

* gnu/packages/cmake.scm (cmake): Simplify the synopsis.
* gnu/packages/version-control.scm (subversion): Remove "open-source"
  from the description.

gnu/packages/cmake.scm

@@ -67,7 +67,7 @@
     (inputs
      `(("file" ,file)))
     (home-page "http://www.cmake.org/")
-    (synopsis "A cross-platform, open-source build system")
+    (synopsis "Cross-platform build system")
     (description
      "CMake is a family of tools designed to build, test and package software.
 CMake is used to control the software compilation process using simple platform

gnu/packages/version-control.scm

@@ -253,8 +253,8 @@ and offers an easy and intuitive interface.")
     (home-page "http://subversion.apache.org/")
     (synopsis "Subversion, a revision control system")
     (description
-     "Subversion exists to be universally recognized and adopted as an
-open-source, centralized version control system characterized by its
+     "Subversion exists to be universally recognized and adopted as a
+centralized version control system characterized by its
 reliability as a safe haven for valuable data; the simplicity of its model and
 usage; and its ability to support the needs of a wide variety of users and
 projects, from individuals to large-scale enterprise operations.")