strace.c: use *_func_* message printing macros where appropriate

strace.c: use *_func_* message printing macros where appropriate

In order to provide some additional bits of information in weird error
cases or just replace existing usages of __func__/literal function name.

* strace.c (detach): Use perror_func_msg() instead of perror_msg().
(startup_attach, open_dummy_desc, startup_child, test_ptrace_seize): Use
perror_func_msg_and_die() instead of perror_msg_and_die().
(test_ptrace_seize): Use error_func_msg_and_die() instead of
error_msg_and_die().