net: shell: conn: Cross-ref TCP control block to owning context

Previously "conn" command dumped TCP control blocks without
referencing it to an owning context, making it hard to figure
out what happens. Now, dump context address.

Example before:

net> conn
     Context    Iface         Flags Local               Remote
[ 1] 0x00403360 0x0041fac0    6ST   [::]:4242   [::]:0
[ 2] 0x004033c8 0x0041fac0    4ST   0.0.0.0:4242        0.0.0.0:0
[ 3] 0x00403430 0x0041fac0    6DU   [::]:4242   [::]:0
[ 4] 0x00403498 0x0041fac0    4DU   0.0.0.0:4242        0.0.0.0:0
[ 5] 0x00403500 0x0041fac0    4ST   192.0.2.1:4242      192.0.2.2:55314

TCP        Src port  Dst port   Send-Seq   Send-Ack  MSS
0x00403c00     4242         0 2541690653          0  1440
0x00403cbc     4242         0 2797902539 3233948882  1460
0x00403d78     4242     55314 2797902539 3233948882  1460

Example after:

net> conn
     Context    Iface         Flags Local               Remote
[ 1] 0x00403360 0x0041fac0    6ST   [::]:4242   [::]:0
[ 2] 0x004033c8 0x0041fac0    4ST   0.0.0.0:4242        0.0.0.0:0
[ 3] 0x00403430 0x0041fac0    6DU   [::]:4242   [::]:0
[ 4] 0x00403498 0x0041fac0    4DU   0.0.0.0:4242        0.0.0.0:0
[ 5] 0x00403500 0x0041fac0    4ST   192.0.2.1:4242      192.0.2.2:55424

TCP        Context   Src port Dst port   Send-Seq   Send-Ack  MSS
0x00403c00 0x00403360    4242        0 1854382523          0  1440
0x00403cbc 0x004033c8    4242        0 1420360158 2064582979  1460
0x00403d78 0x00403500    4242    55424 1420360158 2064582979  1460

Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>