Unlike the kernel script (where plain "riscv" was correct because that's
what the kernel uses, making no distinction between riscv32 and riscv64
in the uapi header directories), this should say "riscv64" because
that's what our build system uses.
(This wasn't caught because we haven't wired up the .bp file yet.)
Test: treehugger
Change-Id: I086aaa89e69bf4ddc484a7e93a6c413fd8c719ff
Rather than "whatever people have installed as 'python' on their machine".
I've removed check-symbols.py because that's been broken for years and
we never even noticed, and I'm not sure it's worth fixing.
Test: treehugger, manual
Change-Id: Ieb996bbdf790a18d4b1fb46a409cc240ba2a2a49
