r176215 corrected readlink(2)'s return type and the type of the last
argument. readlink(2) was introduced in r177788 after being developed
as part of Google Summer of Code 2007; it appears to have inherited the
wrong return type.
Man pages and header files were already ssize_t; update syscalls.master
to match.
PR: 197915
Submitted by: Henning Petersen <henning.petersen@t-online.de>
MFC after: 2 weeks
e8ee7d9035