use CARGO_HOME instead of HOME when building with rust

src/rust/tor_util/include.am

@@ -7,7 +7,7 @@ EXTRA_DIST +=\
 src/rust/target/release/libtor_util.a: FORCE
 	( cd "$(abs_top_srcdir)/src/rust/tor_util" ; \
 		CARGO_TARGET_DIR="$(abs_top_builddir)/src/rust/target" \
-		HOME="$(abs_top_builddir)/src/rust" \
+		CARGO_HOME="$(abs_top_builddir)/src/rust" \
 		$(CARGO) build --release --quiet $(CARGO_ONLINE) )
 
 FORCE:

src/test/test_rust.sh

@@ -7,7 +7,7 @@ exitcode=0
 
 for crate in $crates; do
     cd "${abs_top_srcdir:-.}/src/rust/${crate}"
-    CARGO_TARGET_DIR="${abs_top_builddir}/src/rust/target" HOME="${abs_top_builddir}/src/rust" "${CARGO:-cargo}" test ${CARGO_ONLINE-"--frozen"} || exitcode=1
+    CARGO_TARGET_DIR="${abs_top_builddir}/src/rust/target" CARGO_HOME="${abs_top_builddir}/src/rust" "${CARGO:-cargo}" test ${CARGO_ONLINE-"--frozen"} || exitcode=1
 done
 
 exit $exitcode