poky-init-build-env: Don't exit from sourced scripts, return

git-svn-id: https://svn.o-hand.com/repos/poky/trunk@2227 311d38ba-8fff-0310-9ca6-ca027cbcb966

poky-init-build-env

@@ -21,7 +21,7 @@
 
 if test x"$0" = x"./poky-init-build-env"; then
    echo "Error: Run via '. ./poky-init-build-env'"
-   exit 1
+   return
 fi
 
 . ./scripts/poky-env-internal