[coro.generator.promise] Remove unused name "x"

tkoeppe · tkoeppe · commit 3f47d2565f26 · 2022-11-15T06:11:10.000Z
Fixes NB US 120 (C++23 CD).
diff --git a/source/ranges.tex b/source/ranges.tex
@@ -15313,7 +15313,7 @@
 A handle referring to the coroutine
 whose promise object is \tcode{*this}
 is at the top of \tcode{*\exposid{active_}}
-of some \tcode{generator} object \tcode{x}.
+of some \tcode{generator} object.
 
 \pnum
 \returns
