printf: should warn on excess arguments but doesn't

[jfinkels]

Environment: Ubuntu 20.04, uutils main branch (git commit ceb0785), GNU coreutils v9.6.3-3189c-dirty

Steps to reproduce:

printf "B\n" 1

What happens now: uutils printf prints B with no warning:

B

What I expected to happen: GNU printf prints B with a warning about the excess argument 1:

B
printf: warning: ignoring excess arguments, starting with ‘1’

Notes: this is causing a failure in GNU test file tests/printf/printf-cov.pl.