net: dsa: b53: check for timeout

clang static analysis reports this problem

b53_common.c:1583:13: warning: The left expression of the compound
assignment is an uninitialized value. The computed value will
also be garbage
ent.port &= ~BIT(port);
~~~~~~~~ ^

ent is set by a successful call to b53_arl_read(). Unsuccessful
calls are caught by an switch statement handling specific returns.
b32_arl_read() calls b53_arl_op_wait() which fails with the
unhandled -ETIMEDOUT.

So add -ETIMEDOUT to the switch statement. Because
b53_arl_op_wait() already prints out a message, do not add another
one.

Fixes: 1da6df85c6fb ("net: dsa: b53: Implement ARL add/del/dump operations")
Signed-off-by: Tom Rix <[e-mail]>
Acked-by: Florian Fainelli <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/dsa/b53/b53_common.c

···
 		return ret;
 
 	switch (ret) {
+	case -ETIMEDOUT:
+		return ret;
 	case -ENOSPC:
 		dev_dbg(dev->dev, "{%pM,%.4d} no space left in ARL\n",
 			addr, vid);