Revert "Bluetooth: fix shutdown on SCO sockets"

Revert "Bluetooth: fix shutdown on SCO sockets"

This reverts commit 5e3a563822e1a97203e38a6799f3192bcc97f082.

Quoth Gustavo F. Padovan:
  "Commit 5e3a563822e1a97203e38a6799f3192bcc97f082 can cause a NULL
   dereference if we call shutdown in a bluetooth SCO socket and doesn't
   wait the shutdown completion to call close().  Please revert it.  I
   may have a fix for it soon, but we don't have time anymore, so revert
   is the way to go.  ;)"

Requested-by: Gustavo F. Padovan <padovan@profusion.mobi>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>