fix calling conventions
When a function is assigned to a function pointer that is declared
with a particular calling convention, then the assigned function
must be declared with that calling convention as well. Otherwise,
kaboom!!!
The following functions are fixed by this change:
kuser/kx509.c
validate1()
add1_2chain()
lib/base/log.c
log_syslog()
close_syslog()
log_file()
close_file()
lib/gssapi/mech/context.c
gss_set_log_function()
lib/krb5/kx509.c
certs_export_func()
Change-Id: Ib68abf739e3385e98136fa4e4f5a0240e9fce033