Change comparisons with function pointers to comparisons with SENs

* pathtrace.c (pathtrace_match): Change all comparisons with function
pointers to a single SEN based switch.
* syscall.c (dumpio, trace_syscall_entering): Change all comparisons
with function pointers to comparisons with SENs.
* ipc.c (sys_ipc): Remove.
* sock.c (sys_socketcall): Likewise.
* linux/dummy.h (sys_ipc, sys_socketcall): New aliases.
5 files changed