[pairs.pair] Consistent wording for assignment

Apply a consistent pattern to how we specify assigning members in assignment operators.

Author: AlisdairM

source/utilities.tex

@@ -1075,8 +1075,8 @@
 
 \pnum
 \effects
-Assigns to \tcode{first} with \tcode{std::forward<T1>(p.first)}
-and to \tcode{second} with \tcode{std::forward<T2>(\brk{}p.second)}.
+Assigns \tcode{std::forward<T1>(p.first)} to \tcode{first} and
+\tcode{std::forward<T2>(p.second)} to \tcode{second}.
 
 \pnum
 \returns
@@ -1130,8 +1130,8 @@
 
 \pnum
 \effects
-Assigns to \tcode{first} with \tcode{std::forward<U1>(p.first)}
-and to \tcode{second} with\\ \tcode{std::forward<U2>(p.second)}.
+Assigns \tcode{std::forward<U1>(p.first)} \tcode{first} and
+\tcode{std::forward<U2>(p.second)} to \tcode{second}.
 
 \pnum
 \returns