Fix VS 2008 generation with nested folders again
Fix VS 2008 generation with nested folders again

Follow up to r1831, which forgot to adjust one of the call sites of _ConvertSourcesToFilterHierarchy.

Patch from stk.haller@googlemail.com.

R=jochen@chromium.org

Review URL: https://codereview.chromium.org/135903007
witwall/gyp,witwall/gyp,witwall/gyp,witwall/gyp,witwall/gyp