objtool/klp: Add test for tracepoint and pr_debug static branch keys

A module-owned static branch key is normally fatal, because late module
patching lets the livepatch load before the module it depends on and
jump_label_add_module() then dereferences an unresolved entry.

Tracepoints and pr_debug() generate such keys everywhere, so refusing them
outright would make any function containing a trace_*() call or a
pr_debug() unpatchable.  klp diff drops the entry, warns, and carries on:
the patched code works with that one tracepoint or debug print permanently
off.

Both halves matter, and the test asserts both.  A build which fails is a
function nobody can patch; an entry left in place is the corruption the
rejection exists to prevent.

Give the fixture a KEY_NAME knob so the same static branch can be built
with either special name.  Verified by removing each exemption in turn --
the test fails for both.  That the entry is then dropped is asserted but
not isolated, and the test says so.

Assisted-by: Claude:claude-opus-4
Based-on-test-by: Joe Lawrence <joe.lawrence@redhat.com>
Assisted-by: Claude:claude-opus-5
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://patch.msgid.link/20260916184351.2720310-50-song@kernel.org

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