Fix ByteBuf.nioBuffer(...) and nioBuffers(...) docs to reflect reality.
Fix ByteBuf.nioBuffer(...) and nioBuffers(...) docs to reflect reality.

Motivation:

Depending on the implementation of ByteBuf nioBuffer(...) and nioBuffers(...) may either share the content or return a ByteBuffer that contains a copy of the content.

Modifications:

Fix javadocs.

Result:

Correct docs.

kiril-me/netty,kiril-me/netty,kiril-me/netty,kiril-me/netty,kiril-me/netty