Fix two more coverity constant expression result findings.

These correspond to findings 0 and 1 in the core findings of
ASTERISK-19649.

After contacting Mark Spencer, he was unsure of what the intent
behind these lines of code were, so they are being axed.

For Asterisk 1.8 and 10, the output of debugging DUNDi frames
will not be changed, but for trunk the "Retry" portion will
be omitted since it does not properly distinguish retransmissions
from initial frames.

(closes issue ASTERISK-19649)
Reported by Matthew Jordan
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Merged revisions 366409 from http://svn.asterisk.org/svn/asterisk/branches/1.8
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Merged revisions 366412 from http://svn.asterisk.org/svn/asterisk/branches/10


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@366413 65c4cc65-6c06-0410-ace0-fbb531ad65f3