RFR [XXS] 8134356: {@code} tag contains < and > sequences

[Ivan Gerasimov]

Hi!

In a few places {@code } block contains < and > sequences, which 
are displayed verbatim in the doc.
Would you please help review the trivial cleanup?

BUGURL: https://bugs.openjdk.java.net/browse/JDK-8134356
WEBREV: http://cr.openjdk.java.net/~igerasim/8134356/00/webrev/

Sincerely yours,
Ivan