[lldb-dotest] Wrap arguments in single quotes

If we don't wrap arguments to the wrapper in single quotes, combined
arguments, for example for -E, don't reach dotest.py as a unit but as
separate arguments, causing the latter to fail.

git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@328020 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed