Fix(&put): &put bug with choices

[wjrforcyber]

Related: #349

This PR fix the bug when &put is used with choice network.
It used to fail on an assert:

ABC command line: "read_aiger i10.aig; strash; choice; ps; &get; &ps; &put; ps".

i10                           : i/o =  257/  224  lat =    0  and =   3764 (choice = 541)  lev = 51
i10      : i/o =    257/    224  and =    3764  lev =   51 (16.05)  mem = 0.05 MB
cst =       0  cls =    541  lit =     587  unused =    2893  proof =     0
Error: Transforming AIG with 541 choice nodes.
Assertion failed: (pTemp->pData != NULL), function Abc_NtkFromDarChoices, file abcDar.c, line 1227.
[1]    69583 abort      ./abc -c "read_aiger i10.aig; strash; choice; ps; &get; &ps; &put; ps"

After fix (cec checked):

ABC command line: "read_aiger i10.aig; strash; choice; ps; &get; &ps; &put; ps; cec -n i10.aig".

i10                           : i/o =  257/  224  lat =    0  and =   3764 (choice = 541)  lev = 51
i10      : i/o =    257/    224  and =    3764  lev =   51 (16.05)  mem = 0.05 MB
cst =       0  cls =    541  lit =     587  unused =    2893  proof =     0
Warning: Transforming AIG with 541 choice nodes.
i10                           : i/o =  257/  224  lat =    0  and =   3764 (choice = 541)  lev = 51
Warning: The choice nodes in the original AIG are removed by strashing.
Networks are equivalent.  Time =     0.32 sec

The reason would be some choices are not even created when comparing, so assign the relations after creating the whole network would be good to go.