systemc: Exclude another test which exercises sc_string.

Change-Id: Ic05fe3d34ef403dd6ad9348478f73c6ed50cc7bc
Reviewed-on: https://gem5-review.googlesource.com/11264
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>
1 file changed