nice: Permit --adjustment to be specified multiple times
This is tested by the GNU coreutils test suite, and the
correct behaviour is the last specification wins.
@@ -190,6 +190,8 @@ pub fn uu_app() -> Command {
.short('n')
.long(options::ADJUSTMENT)
.help("add N to the niceness (default is 10)")
+ .action(ArgAction::Set)
+ .overrides_with(options::ADJUSTMENT)
.allow_hyphen_values(true),
)
.arg(
