rockspec: call luke with the Lua binary probed by luarocks.
rockspec: call luke with the Lua binary probed by luarocks.

Closes #285
* luaposix-git-1.rockspec (build.build_command): Prefix with luarocks
expanded $(LUA), otherwise the `#! /usr/bin/env lua` shell magic in
build-aux/luke, which may not match the binary installed by the user.

Reported-by: Gregory Johnson
Signed-off-by: Gary V. Vaughan <f9023000f29773649f3850298becb9544b5fd6a9@gnu.org>

luaposix/luaposix