librados.cc: use static_cast instead of c-style cast

Signed-off-by: Danny Al-Gaaf <danny.al-gaaf@bisect.de>
fuse_ll.cc: use reinterpret_cast instead of c-style cast

Signed-off-by: Danny Al-Gaaf <danny.al-gaaf@bisect.de>
Paxos.cc: use reinterpret_cast instead of c-style cast

Signed-off-by: Danny Al-Gaaf <danny.al-gaaf@bisect.de>