[ostream.formatted.print, print.fun] Move "only" to a clearer place

In wording for LWG4044, as per LWG discussion.

Author: burblebee

source/iostreams.tex

@@ -6865,7 +6865,7 @@
 \item
 If the function is \tcode{vprint_unicode} and
 \tcode{os} is a stream that refers to a terminal that
-is only capable of displaying Unicode via a native Unicode API,
+is capable of displaying Unicode only via a native Unicode API,
 which is determined in an implementation-defined manner,
 flushes \tcode{os} and then
 writes \tcode{out} to the terminal using the native Unicode API;
@@ -7846,7 +7846,7 @@
 \begin{itemize}
 \item
 If \tcode{stream} refers to a terminal that
-is only capable of displaying Unicode via a native Unicode API,
+is capable of displaying Unicode only via a native Unicode API,
 flushes \tcode{stream} and then
 writes \tcode{out} to the terminal using the native Unicode API;
 if \tcode{out} contains invalid code units,