instrument: README: fix invocation

Author: fw-immunant

dynamic_instrumentation/README.md

@@ -1,9 +1,10 @@
 ```sh
-cargo run -- analysis_metadata.bc ../analysis/tests/misc/src/main.rs -L ~/.rustup/toolchains/nightly-2022-02-14-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/ -L ../target/debug/deps/ --extern c2rust_analysis_rt=../target/debug/deps/libc2rust_analysis_rt-4c5a3dcb09c8161c.rlib
-INSTRUMENT_BACKEND=debug METADATA_FILE=analysis_metadata.bc ./main
+cargo build
+${CARGO_TARGET_DIR:-../target/debug/c2rust-instrument} --metadata instrument.target/debug/metadata.bc -- build --manifest-path analysis/tests/misc/Cargo.toml
+(cd analysis/tests/misc/instrument.target/debug; INSTRUMENT_BACKEND=debug INSTRUMENT_RUNTIME=bg METADATA_FILE=metadata.bc ./c2rust-analysis-tests-misc)
 ```
 
 This instruments the binary built from main.rs with dynamic memory tracing, and
 outputs the necessary metadata to match up instrumentation points to source code
-into `analysis_metadata.bc`. We then run the binary, printing output to the
+into `metadata.bc`. We then run the binary, printing output to the
 debug console and using the aformentioned metadata file.