MoH: Undo commit r416150 (1.8)

This patch reverts r416150. When the comparison between mohclass->name and
state->class->name is made, you are not guaranteed that (a) state->class is
non-NULL or that state or state->class are in a safe state.

Crashes caught by the bridges/transfer_capabilities test.
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Merged revisions 416251 from http://svn.asterisk.org/svn/asterisk/branches/1.8
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Merged revisions 416252 from http://svn.asterisk.org/svn/asterisk/branches/11
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Merged revisions 416255 from http://svn.asterisk.org/svn/asterisk/branches/12


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@416267 65c4cc65-6c06-0410-ace0-fbb531ad65f3