ldocs: posix.sys.socket.recv returns a string of bytes
Fixes
* ext/posix/sys/socket.c (recv): Fix the return type in the docs.
@@ -493,7 +493,7 @@ Receive a message from a socket.
@function recv
@int fd socket descriptor to act on
@int count maximum number of bytes to receive
-@treturn[1] int received bytes, if successful
+@treturn[1] string received bytes, if successful
@return[2] nil
@treturn[2] string error message
@treturn[2] int errnum
