ftrace: Add back ftrace_update_trampoline() to ftrace_update_pid_func()

ftrace: Add back ftrace_update_trampoline() to ftrace_update_pid_func()

The update to the ops trampoline done by the function
ftrace_update_trampoline() was accidentally removed from
ftrace_update_pid_func(). Add it back.

Link: https://lore.kernel.org/linux-trace-kernel/20240605205337.6115e9a5@gandalf.local.home
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Fixes: df3ec5da6a1e ("function_graph: Add pid tracing back to function graph tracer")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>