[allocator.requirements] Removed unused variables r and s in Table 27.

Author: jacobsa

source/lib-intro.tex

@@ -1652,11 +1652,6 @@
   conversion from a value \tcode{p}  \\ \rowsep
 \tcode{z}       &   a value of type \tcode{XX::const_void_pointer} obtained by
   conversion from a value \tcode{q} or a value \tcode{w}  \\ \rowsep
-\tcode{r}       &   a value of type \tcode{T\&}
-obtained by the expression \tcode{*p}.                  \\ \rowsep
-\tcode{s}       &   a value of type \tcode{const T\&}
-obtained by the expression \tcode{*q} or by conversion from
-a value \tcode{r}.                                      \\ \rowsep
 \tcode{u}       &   a value of type \tcode{XX:const_void_pointer} obtained by
 conversion from a result value of \tcode{YY::allocate}, or else a value of
 type (possibly \tcode{const}) \tcode{std::nullptr_t}. \\ \rowsep