net: thunder_bgx: decrement cleanup index before use

net: thunder_bgx: decrement cleanup index before use

[ Upstream commit 9e3d71a92e561ccc77025689dab25d201fee7a3e ]

All paths in probe that call goto defer do so before assigning phydev
and thus it makes sense to cleanup the prior index. It also fixes a bug
where index 0 does not get cleaned up.

Fixes: b7d3e3d3d21a ("net: thunderx: Don't leak phy device references on -EPROBE_DEFER condition.")
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250901213314.48599-1-rosenp@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>