go-build: export GO111MODULE=off

We aren't setup for go module builds, so we need to disable it
in the go-build recipe.

Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>

recipes-devtools/go/go-build_git.bb

@@ -44,6 +44,7 @@ do_compile() {
     export CC="${CC}"
     export LD="${LD}"
     export GOBIN=""
+    export GO111MODULE=off
 
     oe_runmake GO=${GO}
 }