Documentation: consistently use spaces inside initializers

Our coding guide is inconsistent with how it uses spaces inside of
initializers (`struct foo bar = { something }`). While we mostly carry
the space between open and closing braces and the initialized members,
in one case we don't.

Fix this one instance such that we consistently carry the space. This is
also consistent with how clang-format formats such initializers.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: pks-t

Documentation/CodingGuidelines

@@ -244,7 +244,7 @@ For C programs:
    . since around 2007 with 2b6854c863a, we have been using
      initializer elements which are not computable at load time. E.g.:
 
-	const char *args[] = {"constant", variable, NULL};
+	const char *args[] = { "constant", variable, NULL };
 
    . since early 2012 with e1327023ea, we have been using an enum
      definition whose last element is followed by a comma.  This, like