the DAHDI_GETCONF, DAHDI_SETCONF and DAHDI_GET_PARAMS ioctls were recently corrected...

the DAHDI_GETCONF, DAHDI_SETCONF and DAHDI_GET_PARAMS ioctls were recently corrected to show that they do, in fact, read data from userspace as part of their work. due to this fix, valgrind now reports a number of cases where chan_dahdi passed an uninitialized (or partially) buffer to these ioctls, which could lead to unexpected behavior.

this patch corrects chan_dahdi to ensure that buffers passed to these ioctls are always fully initialized.

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@185952 65c4cc65-6c06-0410-ace0-fbb531ad65f3