lua_checkstack documentation nitpick

[Alexander Gladysh <agladysh@...>]

Hi, list!

Quoting http://www.lua.org/manual/5.1/manual.html#lua_checkstack (with
my emphasis):

"Ensures that there are at least extra free stack slots in the stack.
It returns *false* if it cannot grow the stack to that size. This
function never shrinks the stack; if the stack is already larger than
the new size, it is left unchanged."

I believe that to be consistent with the rest of Lua C API docs, it
should say "It returns *0* if it cannot grow the stack to that size."
It may also make sense to add something like "Otherwise returns a
non-zero value."

HTH,
Alexander.