Return code for unsolicited arping is 1 instead of 0

When running a gratuitous / unsolicited arp via "arping -U" on Ubuntu Focal
a return code of 1 is given, instead of always 0 (as there is no arp reply expected).

Focal:
--- cut ---
# arping -U -c1 -I eth0 127.0.0.1; echo "ReturnCode: $?"
ARPING 127.0.0.1 from 127.0.0.1 eth0
Sent 1 probes (1 broadcast(s))
Received 0 response(s)
ReturnCode: 1

# arping -V
arping from iputils s20190709
--- cut ---

see corresponding source at https://github.com/iputils/iputils/blob/13e00847176aa23683d68fce1d17ffb523510946/arping.c#L302.

On Ubuntu Bionic this worked fine (and also does on Ubuntu Hirsute again BTW):
--- cut ---
arping -U -c 1 -I eth0 127.0.0.1; echo "ReturnCode: $?"
ARPING 127.0.0.1 from 127.0.0.1 eth0
Sent 1 probes (1 broadcast(s))
Received 0 response(s)
ReturnCode: 0

# arping -V
arping utility, iputils-s20161105
--- cut ---

see corresponding source for that version at https://github.com/iputils/iputils/blob/bffc0e957b98d626ab4cea218c89251201425442/arping.c#L329 or for the version on Hirsute at https://github.com/iputils/iputils/blob/cc16da6b574ce6637f3e6e9ab3c1a728663006ff/arping.c#L302

As you can see by looking at the source arping always statically returns a "0" for unsolicited.