Fix spelling.

Followup to r1648014 to unreak compilation.


git-svn-id: https://svn.apache.org/repos/asf/tomcat/jk/trunk@1648052 13f79535-47bb-0310-9956-ffa450edef68
Rename new defines from *_SIZE to *_LEN to reflect
more clearly their meaning (string length excluding
final '\0'.

We don't use this convention everywhere, but it
will soon help to make a distinction to
JK_SHM_STR_SIZ.


git-svn-id: https://svn.apache.org/repos/asf/tomcat/jk/trunk@1648054 13f79535-47bb-0310-9956-ffa450edef68