Fix whitespace in previous change.

doc/lispref/lists.texi

@@ -1267,7 +1267,7 @@ functions for sets include @code{memq} and @code{delq}, and their
 @quotation
 @b{Common Lisp note:} Common Lisp has functions @code{union} (which
 avoids duplicate elements) and @code{intersection} for set operations.
-Although standard GNU Emacs Lisp does not have them,  the @file{cl}
+Although standard GNU Emacs Lisp does not have them, the @file{cl}
 library provides versions.  @inforef{Top, Overview, cl}.
 @end quotation