com-display-directory loses on asking new pathname

[Robert W. Kerns <RWK at SCRC-TENEX>]

In ZWEI in Experimental System 204.23, Experimental ZMail 42.3,
Experimental LMFS 23.18, Experimental Tape 8.0,
Experimental Symbolics 10.1, Experimental Canon 12.1, microcode 865, on Beagle:

When COM-DISPLAY-DIRECTORY asks for a new pathname, when it displays
the directory, the pathname it displays at the top of the screen is
the original one, not the corrected one.  E.g. ^U^X^D SCRC:<LMMAN>*.XGP
and when you get the bogus TENEX error, give it <RWK>*.XGP instead.