Inputs always crash if workdir contains colon

[fwc]

When running hongfuzz on a trivial LLVMFuzzerTestOneInput harness from a directory that contains a : like e.g. foo:bar, honggfuzz reports all tested inputs as crashes:

The following Dockerfile reproduces the behaviour (on my machines):

FROM ubuntu@sha256:35f3a8badf2f74c1b320a643b343536f5132f245cbefc40ef802b6203a166d04
WORKDIR /honggfuzz

RUN apt -y update
RUN apt -y install binutils-dev libunwind-dev libblocksruntime-dev clang make

ADD https://github.com/google/honggfuzz.git#ded8c87bcf3cc32f64c1097746a3461d6da1c24a .
RUN make && make install

COPY <<EOF /harness.cpp
#include <cstddef>
#include <cstdint>

extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
	return 0;
}
EOF

RUN hfuzz-clang++ -fsanitize=fuzzer /harness.cpp -o /harness

COPY <<EOF /entrypoint.sh
mkdir /input

mkdir /foo:bar
cd /foo:bar
timeout 10s honggfuzz -i /input -o . -- /harness
EOF

ENTRYPOINT [ "bash", "/entrypoint.sh" ]