Fix an error in tramp-vc-file-name-handler

Fix an error in tramp-vc-file-name-handler

* lisp/net/tramp.el (tramp-accept-process-output, tramp-send-string):
* lisp/net/tramp-adb.el (tramp-adb-handle-make-process):
* lisp/net/tramp-sh.el (tramp-do-copy-or-rename-file-out-of-band)
(tramp-sh-handle-make-process):
* lisp/net/tramp-smb.el (tramp-smb-handle-copy-directory)
(tramp-smb-handle-file-acl, tramp-smb-handle-process-file)
(tramp-smb-handle-set-file-acl)
(tramp-smb-handle-start-file-process): Do not suppress timers.

* lisp/net/tramp-sh.el (tramp-vc-file-name-handler): Check, that
`tramp-file-name-for-operation' returns a proper Tramp file.