Fix major status handling in gss_acquire_cred.

If we have at least one cred element after the mech loop, reset major
before continuing on, or we could mistakenly return a failure status
from the last mech (and free the returned creds).  Reported by
aberry@likewise.com.

https://github.com/krb5/krb5/commit/167aed220154427f3a7b5dbb859d93b773c08992
Commit By: ghudson
Revision: 25097
Changed Files:
U   trunk/src/lib/gssapi/mechglue/g_acquire_cred.c