Revert "debugfs, coccinelle: check for obsolete DEFINE_SIMPLE_ATTRIBUTE() usage"

Remove coccinelle's recommendation to use DEFINE_DEBUGFS_ATTRIBUTE()
instead of DEFINE_SIMPLE_ATTRIBUTE().  Regardless of whether or not the
"significant overhead" incurred by debugfs_create_file() is actually
meaningful, warnings from the script have led to a rash of low-quality
patches that have sowed confusion and consumed maintainer time for little
to no benefit.  There have been no less than four attempts to "fix" KVM,
and a quick search on lore shows that KVM is not alone.

This reverts commit 5103068e.

Link: https://lore.kernel.org/all/87tu2nbnz3.fsf@mpe.ellerman.id.au
Link: https://lore.kernel.org/all/c0b98151-16b6-6d8f-1765-0f7d46682d60@redhat.com
Link: https://lkml.kernel.org/r/20230706072954.4881-1-duminjie%40vivo.com
Link: https://lore.kernel.org/all/Y2FsbufV00jbyF0B@google.com
Link: https://lore.kernel.org/all/Y2ENJJ1YiSg5oHiy@orome
Link: https://lore.kernel.org/all/7560b350e7b23786ce712118a9a504356ff1cca4.camel@kernel.orgSuggested-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20230726202920.507756-1-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

scripts/coccinelle/api/debugfs/debugfs_simple_attr.cocci

-// SPDX-License-Identifier: GPL-2.0
-/// Use DEFINE_DEBUGFS_ATTRIBUTE rather than DEFINE_SIMPLE_ATTRIBUTE
-/// for debugfs files.
-///
-//# Rationale: DEFINE_SIMPLE_ATTRIBUTE + debugfs_create_file()
-//# imposes some significant overhead as compared to
-//# DEFINE_DEBUGFS_ATTRIBUTE + debugfs_create_file_unsafe().
-//
-// Copyright (C): 2016 Nicolai Stange
-// Options: --no-includes
-//
-
-virtual context
-virtual patch
-virtual org
-virtual report
-
-@dsa@
-declarer name DEFINE_SIMPLE_ATTRIBUTE;
-identifier dsa_fops;
-expression dsa_get, dsa_set, dsa_fmt;
-position p;
-@@
-DEFINE_SIMPLE_ATTRIBUTE@p(dsa_fops, dsa_get, dsa_set, dsa_fmt);
-
-@dcf@
-expression name, mode, parent, data;
-identifier dsa.dsa_fops;
-@@
-debugfs_create_file(name, mode, parent, data, &dsa_fops)
-
-
-@context_dsa depends on context && dcf@
-declarer name DEFINE_DEBUGFS_ATTRIBUTE;
-identifier dsa.dsa_fops;
-expression dsa.dsa_get, dsa.dsa_set, dsa.dsa_fmt;
-@@
-* DEFINE_SIMPLE_ATTRIBUTE(dsa_fops, dsa_get, dsa_set, dsa_fmt);
-
-
-@patch_dcf depends on patch expression@
-expression name, mode, parent, data;
-identifier dsa.dsa_fops;
-@@
-- debugfs_create_file(name, mode, parent, data, &dsa_fops)
-+ debugfs_create_file_unsafe(name, mode, parent, data, &dsa_fops)
-
-@patch_dsa depends on patch_dcf && patch@
-identifier dsa.dsa_fops;
-expression dsa.dsa_get, dsa.dsa_set, dsa.dsa_fmt;
-@@
-- DEFINE_SIMPLE_ATTRIBUTE(dsa_fops, dsa_get, dsa_set, dsa_fmt);
-+ DEFINE_DEBUGFS_ATTRIBUTE(dsa_fops, dsa_get, dsa_set, dsa_fmt);
-
-
-@script:python depends on org && dcf@
-fops << dsa.dsa_fops;
-p << dsa.p;
-@@
-msg="%s should be defined with DEFINE_DEBUGFS_ATTRIBUTE" % (fops)
-coccilib.org.print_todo(p[0], msg)
-
-@script:python depends on report && dcf@
-fops << dsa.dsa_fops;
-p << dsa.p;
-@@
-msg="WARNING: %s should be defined with DEFINE_DEBUGFS_ATTRIBUTE" % (fops)
-coccilib.report.print_report(p[0], msg)