Consistently use error_msg instead of fprintf(stderr)

* linux/alpha/get_scno.c: Use error_msg.
* linux/arm/get_scno.c: Likewise.
* linux/mips/get_scno.c: Likewise.
* linux/sh/get_scno.c: Likewise.
* linux/x86_64/get_scno.c: Likewise.
* exit.c (sys_exit): Likewise.
* pathtrace.c (pathtrace_select, pathtrace_match): Likewise.
* strace.c (alloctcb, droptcb, detach, startup_attach,
test_ptrace_seize, init, cleanup, print_debug_info,
maybe_allocate_tcb, startup_tcb, trace): Likewise.
* syscall.c (update_personality, trace_syscall_exiting,
get_scno): Likewise.
* unwind.c (DPRINTF): Likewise.
* tests/bexecve.test: Update patterns.
* tests/detach-stopped.test: Likewise.
12 files changed