docs: ras: don't need to repeat twice the same thing

We don't need to say twice "for the first time" at the same
paragraph.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/f76dcae96de8b1bb8ee37a79781c111c825e26d6.1586881715.git.mchehab+huawei@kernel.orgSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/admin-guide/ras.rst

@@ -212,7 +212,7 @@ EDAC - Error Detection And Correction
    purposes.
 
    When the subsystem was pushed upstream for the first time, on
-   Kernel 2.6.16, for the first time, it was renamed to ``EDAC``.
+   Kernel 2.6.16, it was renamed to ``EDAC``.
 
 Purpose
 -------