Change expected result of a flymake test on hydra

* test/lisp/progmodes/flymake-tests.el (different-diagnostic-types):
Test is now passing on hydra.nixos.org, since today.
1 job for master in 132 minutes and 23 seconds (queued for 1 second)
Status Job ID Name Coverage
  Test
failed #2355
test-all

02:12:23

 
Name Stage Failure
failed
test-all Test There has been a timeout failure or the job got stuck. Check your timeout limits or try again
make[2]: Nothing to be done for 'compile-targets'.
make[2]: Leaving directory '/builds/emacs/emacs/lisp'
make[1]: Leaving directory '/builds/emacs/emacs/lisp'
make -C test check-expensive
make[1]: Entering directory '/builds/emacs/emacs/test'
rm -f ./*.tmp
make[2]: Entering directory '/builds/emacs/emacs/test'
make[3]: Entering directory '/builds/emacs/emacs/test'
ELC lisp/net/tramp-tests.elc
GEN lisp/net/tramp-tests.log