Server crashes on 64bit linux with 'double free or corruption'
message, on 32bit mysql-test-run silently fails on bootstrap
stage. The problem is that FreeState() is called twice
for init_settings struct in _db_end_ function.
The fix is to remove superfluous FreeState() call.
Additional fix:
fixed discrepancy of result file when
debug & valgrind options are enabled
for MTR.

dbug/dbug.c:
  The problem is that FreeState() is called twice
  for init_settings struct in _db_end_ function.
  The fix is to remove superfluous FreeState() call.
mysql-test/r/variables_debug.result:
  fixed discrepancy of result file when
  debug & valgrind options are enabled
  for MTR.
mysql-test/t/variables_debug.test:
  fixed discrepancy of result file when
  debug & valgrind options are enabled
  for MTR.
sql/set_var.cc:
  fixed discrepancy of result file when
  debug & valgrind options are enabled
  for MTR.