rust: Install to $(STAGING_DIR)/host

This allows rustc/cargo/etc to be called without having to set PATH, as
$(STAGING_DIR)/host/bin is already in PATH.

This also fixes CARGO_HOME not being set during Host/Configure and
Host/Compile.

Signed-off-by: Jeffery To <jeffery.to@gmail.com>

lang/python/python3-package.mk

@@ -47,7 +47,6 @@ PYTHON3_VARS = \
 	_python_exec_prefix="/usr" \
 	CARGO_BUILD_TARGET="$(RUSTC_TARGET_ARCH)" \
 	CARGO_HOME="$(CARGO_HOME)" \
-	PATH="$(CARGO_HOME)/bin:$(PATH)" \
 	PYO3_CROSS_LIB_DIR="$(PYTHON3_LIB_DIR)" \
 	RUSTFLAGS="$(CARGO_RUSTFLAGS)"