fix usrsock getsockname fail
nsh> usrsocktest
...
Testing group "basic_getsockname" =>
[TEST ASSERT FAILED!]
In function "basic_getsockname_open":
line 170: Assertion `(ssize_t)((ret)) == (ssize_t)((0))' failed.
got value: -1
should be: 0
Group "basic_getsockname": [FAILED]
...
Reference:
GETSOCKNAME(2)
NAME
getsockname - get socket name
...
DESCRIPTION
...
The returned address is truncated if the buffer provided is too small;
in this case, addrlen will return a value greater than was supplied to the call.
Signed-off-by: chao an <anchao@xiaomi.com>