external/boringssl: fix |SSLeay|.

SSLeay is a compatibility function for OpenSSL, but I got it wrong.
It doesn't return a string, it returns a number. This doesn't end up
making any difference, but it fixes a warning when building OpenSSH.

Bug: 21304170
Change-Id: I3e4bb0240b18647cfe2a3ce5869948a4527ff0f0
2 files changed