remove useless checks in Row.c
remove useless checks in Row.c

If objects with different equality metamethods are tested
for equality, the result is always false and no metamethods
are called.

See http://www.lua.org/pil/13.2.html

npge/lua-npge,starius/lua-npge,npge/lua-npge,npge/lua-npge,starius/lua-npge,starius/lua-npge