fix(toolchain_util.sh): Switch from sudo_clobber to sudo tee

sudo_clobber is provided by common.sh which isn't included in the
catalyst environment so call sudo tee (what sudo_clobber does) directly
instead.

build_library/toolchain_util.sh

@@ -168,7 +168,7 @@ install_cross_toolchain() {
     then
         $sudo crossdev --stable --portage "$*" \
             --init-target --target "${cross_chost}"
-        sudo_clobber "${cross_cfg}" <<<"${cross_cfg_data}"
+        $sudo tee "${cross_cfg}" <<<"${cross_cfg_data}" >/dev/null
     fi
 
     # If binary packages are enabled try to just emerge them instead of