fgragh: No need to invoke the function call_filter_check_discard()

fgragh: No need to invoke the function call_filter_check_discard()

The function call_filter_check_discard() has been removed in the
commit 49e4154f4b16 ("tracing: Remove TRACE_EVENT_FL_FILTERED logic"),
from another topic branch. But when merged together with commit
21e92806d39c6 ("function_graph: Support recording and printing the
function return address") which added another call to
call_filter_check_discard(), it caused the build to fail. Since the
function call_filter_check_discard() is useless, it can simply be removed
regardless of being merged with commit 49e4154f4b16 or not.

Link: https://lore.kernel.org/all/20241010134649.43ed357c@canb.auug.org.au/
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Donglin Peng <dolinux.peng@gmail.com>
Link: https://lore.kernel.org/20241010194020.46192b21@gandalf.local.home
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Fixes: 21e92806d39c6 ("function_graph: Support recording and printing the function return address")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>