Fix new doxygen parameter lists

Use [out] instead of [in] for the output parameters of
krb5_c_prfplus() and krb5_c_derive_prfplus().  Also use "out" instead
of "output" for krb5_c_derive_prfplus() to match the parameter name in
the definition.

https://github.com/krb5/krb5/commit/9771826f113708c41c75d7c447d4b870c0f6a78f
Author: Greg Hudson <ghudson@mit.edu>
Commit: 9771826f113708c41c75d7c447d4b870c0f6a78f
Branch: master
 src/include/krb5/krb5.hin |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)