Suppress superfluous messages in tramp-tests

* test/lisp/net/tramp-tests.el (tramp-test10-write-region)
(tramp-test10-write-region-file-precious-flag)
(tramp-test34-connection-local-variables)
(tramp-test36-vc-registered): Let-bind `inhibit-message'.
1 job for master in 55 minutes and 50 seconds (queued for 3 seconds)
Status Job ID Name Coverage
  Test
failed #4402
test-all

00:55:50

 
Name Stage Failure
failed
test-all Test
make[2]: *** [check-doit] Error 1
Makefile:319: recipe for target 'check-doit' failed
make[2]: Leaving directory '/builds/emacs/emacs/test'
Makefile:294: recipe for target 'check-expensive' failed
make[1]: *** [check-expensive] Error 2
make[1]: Leaving directory '/builds/emacs/emacs/test'
Makefile:959: recipe for target 'check-expensive' failed
make: *** [check-expensive] Error 2
ERROR: Job failed: exit code 1