Remove docs that specify which equals() element we return.
Remove docs that specify which equals() element we return.

Fixes https://github.com/google/guava/pull/2052
(only 2 years later!)

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=153209013

mosoft521/guava,typetools/guava,berndhopp/guava,EdwardLee03/guava,DavesMan/guava,Xaerxess/guava,google/guava,xasx/guava,google/guava,rgoldberg/guava,Xaerxess/guava,google/guava,xasx/guava,berndhopp/guava,typetools/guava,DavesMan/guava,mosoft521/guava,EdwardLee03/guava,rgoldberg/guava,mosoft521/guava