Fix whitespace error in EITFixUp::FixNL()
Remove unused member variable m_imr in MBroadcastSocketDevice

The member variable m_imr appears to be a carryover
from a code copy/paste from the multicast socket
class (where it is used for the group address).
It is unused in a broadcast socket.  Remove it.

Fixes coverity 746874
Fixes #11622

NOTE: This modifies the binary ABI version number
      due to the mbroadcastsocket.h changes, so
      make distclean, etc. required.
(cherry picked from commit 5e15740501d9e89c0eba71d8ae97c16c3b737495)

Signed-off-by: Stuart Morgan <smorgan@mythtv.org>