bug#22441: 25.1.50; eww confuses distinct eww-mode buffers

[Mark Oteiza]

>From -Q:

M-x eww RET wikipedia.org RET
M-x rename-buffer RET *eww*<2>
M-x eww RET fsf.org RET
C-x b (default *eww*<2>) RET
G gnu.org RET

The buffer is switched from *eww*<2> to *eww*, and navigates to gnu.org.

In GNU Emacs 25.1.50.1 (x86_64-unknown-linux-gnu, X toolkit, cairo version 
1.14.6, Xaw scroll bars)
 of 2016-01-22 built on logos
Repository revision: 9b2375008348da99b5ec414cd3ca8c4669a12576
Configured using:
 'configure --prefix=/usr --sysconfdir=/etc --libexecdir=/usr/lib
 --localstatedir=/var --without-gconf --without-imagemagick --with-cairo
 --with-modules --with-x-toolkit=lucid 'CFLAGS=-march=x86-64
 -mtune=generic -O0 -pipe -fstack-protector-strong
 --param=ssp-buffer-size=4 -g -fvar-tracking-assignments -g
 -fvar-tracking-assignments'
 LDFLAGS=-Wl,-O0,--sort-common,--as-needed,-z,relro'

Configured features:
XPM JPEG TIFF GIF PNG RSVG CAIRO SOUND GPM DBUS GSETTINGS NOTIFY ACL
GNUTLS LIBXML2 FREETYPE M17N_FLT LIBOTF XFT ZLIB TOOLKIT_SCROLL_BARS
LUCID X11 MODULES

Important settings:
  value of $LC_COLLATE: C
  value of $LANG: en_US.UTF-8
  locale-coding-system: utf-8-unix