[class] Clarify 'cv-void class members'

Author: tkoeppe

source/classes.tex

@@ -1140,7 +1140,7 @@
 \indextext{definition!static member}%
 The declaration of a \tcode{static} data member in its class definition
 is not a definition and may be of an incomplete type other than
-cv-qualified \tcode{void}. The definition for a \tcode{static} data
+\cv\ \tcode{void}. The definition for a \tcode{static} data
 member shall appear in a namespace scope enclosing the member's class
 definition.
 \indextext{operator~use!scope~resolution}%