scripts/faddr2line: Don't filter out non-function symbols from readelf

As Josh points out in 20230724234734.zy67gm674vl3p3wv@treble:

> Problem is, I think the kernel's symbol printing code prints the
> nearest kallsyms symbol, and there are some valid non-FUNC code
> symbols.  For example, syscall_return_via_sysret.

so we shouldn't be considering only 'FUNC'-type symbols in the output
from readelf.

Drop the function symbol type filtering from the faddr2line outer loop.

Suggested-by: Josh Poimboeuf <jpoimboe@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/r/20230724234734.zy67gm674vl3p3wv@treble


Signed-off-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20231002165750.1661-2-will@kernel.org


Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>