* ndmp-src/ndma_tape.c: Use ndmchan_n_avail_record to guarantee space
  for a record.
* ndmp-src/ndml_chan.c (ndmchan_n_avail_record): New function.
* ndmp-src/ndmlib.h  (ndmchan_n_avail_record): New prototype.


git-svn-id: https://amanda.svn.sourceforge.net/svnroot/amanda/amanda/branches/3_1@3783 a8d146d6-cc15-0410-8900-af154a0219e0