Fix EOF check in kadm5.acl line processing

On platforms where the char type is unsigned, the check for EOF (which
is negative) will always fail, leaving a 255 byte at the end of the
line.  This can cause a syntax error, in turn causing the contents of
kadm5.acl to be ignored.  Fix this bug by removing the cast on EOF.

[ghudson@mit.edu: more precisely describe consequences of bug in
commit message]

https://github.com/krb5/krb5/commit/8fd85a77789496b8d7f8092f6e8a2824bc09a6cf
Author: Robbie Harwood <rharwood@redhat.com>
Committer: Greg Hudson <ghudson@mit.edu>
Commit: 8fd85a77789496b8d7f8092f6e8a2824bc09a6cf
Branch: master
 src/lib/kadm5/srv/server_acl.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)