Make ganesha pass pynfs tests:

GSS1: Already used sequence number should time out.  Not return
RPCSEC_GSS_CTXPROBLEM
GSS6: Sequnce numbers above MAXSEQ should return RPCSEC_GSS_CTXPROBLEM
GSS7: Bad proceedure numbers should return AUTH_BADCRED

(Changed the MAXPROC sentinel to be outside the proc enumeration, also
gave MAXPROC and MAXSEQ RPCSEC_GSS_ prefix for clarity.)

Signed-off-by: Allison Henderson <achender@linux.vnet.ibm.com>
Signed-off-by: Matt Benjamin <matt@linuxbox.com>