[krbdev.mit.edu #7851] Change in behaviour in the kernel keyring ccache

[Greg Hudson via RT]

This is an old bug, predating the 1.12 changes.

When we add a cred key to a keyring ccache, we give it a description by 
just unparsing creds->server.  We don't use the description for 
searching, but it does clarify the output of "keyctl show" or similar.  
For normal usage, this works fine, but in any kind of exotic usage it 
results in credentials overwriting each other when they only match on the 
server name and not other factors such as client name or requested 
authdata.