fix GOPATH in build macros

OBS-URL: https://build.opensuse.org/package/show/devel:languages:go/go?expand=0&rev=134

macros.go

@@ -5,7 +5,7 @@
 #
 
 %go_ver         %(LC_ALL=C rpm -q --qf '%%{epoch}:%%{version}\\n' go | sed -e 's/ (none):/ /' -e 's/ 0:/ /' | grep -v "is not")
-%go_arch        GOARCH
+%go_arch        amd64
 %go_build_ver   %(go version | sed 's/^go version //' | tr -d ' ')
 
 %go_dir          %{_libdir}/go
@@ -95,7 +95,7 @@ install -d %{buildroot}%{_bindir} \
 # See: go help install, go help packages
 %gobuild() \
 export BUILDFLAGS="-s -v -p 4" \
-export GOPATH=%{_builddir}/go:%{go_contribdir} \
+export GOPATH=%{_builddir}/go:%{_libdir}/go/contrib \
 export GOBIN=%{_builddir}/go/bin \
 MOD="" \
 if [ %# -gt 0 ]; then \
@@ -139,7 +139,7 @@ fi \
 %{nil}
 
 %gotest() \
-export GOPATH=%{_builddir}/go \
+export GOPATH=%{_builddir}/go:%{_libdir}/go/contrib  \
 if [ %# -eq 0 ]; then \
   echo "gotest: please specify a valid importpath, see: go help test" \
   exit 1 \