isdnsync: Remove a double close of the isdn device

The fd is already closed above the if statement and Coverity
detected this as a double close.

Fixes: Coverity CID 1040703
1 file changed
tree: ae657738546183096403de920fe9c1f637e21780
  1. debian/
  2. hlrsync/
  3. linux-kernel/
  4. openbsc/
  5. wireshark/
  6. README