perf script: Fix hangup in offline flamegraph report

JIRA: https://issues.redhat.com/browse/RHEL-87957

upstream
========
commit 29bab85
Author: Namhyung Kim <namhyung@kernel.org>
Date: Tue Feb 18 16:05:58 2025 -0800

description
===========
A recent change in the flamegraph script fixed an issue with live mode
but it created another for offline mode.  It needs to pass "-" to -i
option to read from stdin in the live mode.  Actually there's a logic
to pass the option in the perf script code, but the script was written
with "-- $@" which prevented the option to go to the perf script.  So
the previous commit added the hard-coded "-i -" to the report command.

But it's a problem for the offline mode which expects input from a file
and now it's stuck on reading from stdin.  Let's remove the "-i - --"
part and let it pass the options properly to perf script.

Closes: https://lore.kernel.org/linux-perf-users/c41e4b04-e1fd-45ab-80b0-ec2ac6e94310@linux.ibm.com
Fixes: 23e0a63 ("perf script: force stdin for flamegraph in live mode")
    Reported-by: Thomas Richter <tmricht@linux.ibm.com>
    Tested-by: Thomas Richter <tmricht@linux.ibm.com>
    Cc: Anubhav Shelat <ashelat@redhat.com>
    Signed-off-by: Namhyung Kim <namhyung@kernel.org>

Signed-off-by: Anubhav Shelat <ashelat@redhat.com>

Author: AnubhavS1

tools/perf/scripts/python/bin/flamegraph-report

@@ -1,3 +1,3 @@
 #!/bin/bash
 # description: create flame graphs
-perf script -s "$PERF_EXEC_PATH"/scripts/python/flamegraph.py -i - -- "$@"
+perf script -s "$PERF_EXEC_PATH"/scripts/python/flamegraph.py "$@"