net: thunder_bgx: decrement cleanup index before use

[ Upstream commit 9e3d71a ]

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: b7d3e3d ("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>

Author: neheb

drivers/net/ethernet/cavium/thunder/thunder_bgx.c

@@ -1519,11 +1519,11 @@ static int bgx_init_of_phy(struct bgx *bgx)
 	 * for phy devices we may have already found.
 	 */
 	while (lmac) {
+		lmac--;
 		if (bgx->lmac[lmac].phydev) {
 			put_device(&bgx->lmac[lmac].phydev->mdio.dev);
 			bgx->lmac[lmac].phydev = NULL;
 		}
-		lmac--;
 	}
 	of_node_put(node);
 	return -EPROBE_DEFER;