The RHEL packaging files have evidently not been fully updated to account for Jeremy Layton's renaming of cifs.spnego to 'cifs.upcall'.
On a RHEL4 system, the build fails while packaging files due to the file man8/cifs.upcall.8.gz having been installed but left unpackaged.
Will attach patch to rectify this in samba.spec[.tmpl]...
Created attachment 3681 [details]
patch to /packaging/RHEL/samba.spec[.tmpl] to package the cifs.upcall.8.gz file as part of the samba-client package...
Already fixed meanwhile.
Thanks for reporting!