socketpair: extend syscall socketpair tracing information

Decode the socketpair vector pointer into two file descriptors.
This exposes the connected file descriptors to analyses.

As sockerpair is a sub syscall of socketcall in x86_32,
sockerpair override must be disabled for x86_32 and x86_compatmode

Signed-off-by: Jan Willeke <jan.willeke@harman.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>