tracing: wprobe: Use a new seq_print_ip_sym_offset() wrapper

Use a new seq_print_ip_sym_offset() wrapper function instead of
using TRACE_ITER(SYM_OFFSET) mask directly.

Link: https://lore.kernel.org/all/176226550596.59499.18020648957674458755.stgit@devnote2/

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>