bug#36848: 26.2; doc string of `fit-window-to-buffer'

[Drew Adams]

This text:

 If the optional argument 'preserve-size' is non-nil, preserve the
 size of WINDOW (see 'window-preserve-size').

Should be this:

 If the optional argument PRESERVE-SIZE is non-nil, preserve the
 size of WINDOW (see 'window-preserve-size').

A user searching the verbose doc string for parameter PRESERVE-SIZE, and
with nil `case-fold-search', will not find it.

Better yet:

 Non-nil PRESERVE-SIZE means preserve the size of WINDOW (see
 'window-preserve-size').



In GNU Emacs 26.2 (build 1, x86_64-w64-mingw32)
 of 2019-04-13
Repository revision: fd1b34bfba8f3f6298df47c8e10b61530426f749
Windowing system distributor `Microsoft Corp.', version 10.0.17763
Configured using:
 `configure --without-dbus --host=x86_64-w64-mingw32
 --without-compress-install 'CFLAGS=-O2 -static -g3''