Make the sync flag's type consistent in the Socket module

[e-kayrakli]

The Socket module uses a sync variable in some of its functions to wait for some events. This sync variable is passed via c_ptrs to a callback function. However there are inconsistencies in the types used:

• There are 4 places where this happens: 3 of them uses sync c_short, 1 uses sync int
• The callback function assumes that the flag is sync int.

The callbacks seems to write a c_short into this sync variable. Therefore, I assume that c_short is a more correct choice. So, this PR makes the sync variable of c_short type and adjusts the callback.

Test:

• local library/package/Socket