cmake DUNE_SYS_HAS_LIB_V4L2 examples

LSTS/dune cmake/Libraries/V4L2.cmake :36 

else(DUNE_SYS_HAS_LIB_V4L2 AND DUNE_SYS_HAS_LIBV4L2_H)

LSTS/dune cmake/Libraries/V4L2.cmake :38 

endif(DUNE_SYS_HAS_LIB_V4L2 AND DUNE_SYS_HAS_LIBV4L2_H)