do not always add CURDIR to SRC_PATH.
do not always add CURDIR to SRC_PATH.

this alleviates an issue when we build the database containing a parent
directory as well as a subdirectory of that parent in our SRC_PATH and tools
such as cscope do not cope and add definitions multiple times.

prod by Zhihui.


git-svn-id: f2acecaac6fbd5a03f3d4799db58dda434111981@10942 3eda493b-6a19-0410-b2e0-ec8ea4dd8fda

pscedu/slash2-stable,pscedu/slash2-stable,pscedu/slash2-stable,pscedu/pfl,pscedu/pfl,pscedu/pfl,pscedu/slash2-stable,pscedu/slash2-stable,pscedu/pfl,pscedu/slash2-stable,pscedu/slash2-stable