bug#59457: 29.0.50; Incorrect vc-parent-buffer-name on vc-change-log revert

[Gabriel]

Description:

The *vc-change-log* buffer gets an incorrect value of
`vc-parent-buffer-name' on `revert-buffer'.

Steps:

1) emacs -Q (master "f176a36f4629b56c9fd9e3fc15aebd04a168c4f5")

2) Open some VC controlled file, e.g.: C-x C-f ~/git/emacs/README RET

3) Annotate the buffer: C-x v g

4) Show log revision at line: l

Result: *vc-change-log* buffer is displayed; the value of
`vc-parent-buffer-name', displayed on the right side of mode-line (see
`mode-line-format' and `mode-line-modes'), is correct (e.g.: " from
*Annotate README (rev f176a36f4629b56c9fd9e3fc15aebd04a168c4f5)*").

5) Revert the buffer: g

Result: the buffer is refreshed, but the value of
`vc-parent-buffer-name' is incorrectly set as " from *vc-change-log*".

---
Gabriel