btf: re-enable resolve_btfids linker-flag fix (0002)
Run after re-enabling 0001 got past libbpf feature detection but failed
at the final resolve_btfids link: 'clang-12: error: unable to execute
command: Executable "ld" doesn't exist'. The 5.10 resolve_btfids
Makefile links with bare $(LDFLAGS) (empty), so clang falls back to
plain 'ld', which is absent from the hermetic PATH. 0002 sets
LDFLAGS := $(KBUILD_HOSTLDFLAGS), inheriting the hermetic
'-fuse-ld=lld --rtlib=compiler-rt' exported by build/_setup_env.sh, so
the link uses ld.lld. Load-bearing for every android12-5.10 sublevel.