Fix ABI string processing for deqp in CTS

Combined the getting of the current string into the same shell
invocation with the sed processing. Getting parameter value via $(shell
did not seem to work anymore.

Bug: 25322689

(cherry-pick from commit cb40161ae085dcb5f7e3baacffd959ca73863665)

Change-Id: I9e067dc1d5f977bffb5fa3a8a812351d7f873d0f
1 file changed