[flat.map.cons.alloc] Remove superfluous \linebreak (#8745)

Author: Andreas-Krug

source/containers.tex

@@ -17619,7 +17619,7 @@
 \pnum
 \effects
 Equivalent to \tcode{flat_map(sorted_unique, key_cont, mapped_cont)} and
-\tcode{flat_map(sorted_unique, key_cont, \linebreak{}mapped_cont, comp)}, respectively,
+\tcode{flat_map(sorted_unique, key_cont, mapped_cont, comp)}, respectively,
 except that \tcode{\exposid{c}.keys} and \tcode{\exposid{c}.values} are constructed
 with uses-allocator construction\iref{allocator.uses.construction}.