Simplify always evaluated branch (e != NULL)

• xalloc(..) ensures that e will be non-null via malloc + err.
• e is already dereferenced above, so logically it's impossible to hit the lower test without crashing if it was indeed NULL.

MFC after: 3 days
CID: 1007408
Reported by: Coverity
Sponsored by: EMC / Isilon Storage Division