MSVC: Drop /link from executable link lines with Ninja

In commit fb9f73de (MSVC: Invoke 'link' directly for executables,
2013-04-08) we forgot to remove the /link option handling added by
commit e31df039 (Ninja: move <OBJECTS> in front of the first linker
option, 2012-09-27) to the Platform/Windows-MSVC module.  Drop it now.
Merge topic 'ninja-MSVC-link-executables' into next

3cd753d MSVC: Drop /link from executable link lines with Ninja