net: Unbreak userspace which includes linux/mroute.h

net: Unbreak userspace which includes linux/mroute.h

[ Upstream commit 7c19a3d280297d43ef5ff7c6b205dc208a16d3d1 ]

This essentially reverts two commits:

1) 2e8046271f68198dd37451017c1a4a2432e4ec68 ("[IPV4] MROUTE: Move PIM
   definitions to <linux/pim.h>.")

and

2) 80a9492a33dd7d852465625022d56ff76d62174d ("[IPV4] MROUTE: Adjust
   include files for user-space.")

which broke userpsace, in particular the XORP build as reported by
Jose Calhariz, the debain package maintainer for XORP.

Nothing originally in linux/mroute.h was exported to userspace
ever, but some of this stuff started to be when it was moved into
this new linux/pim.h, and that was wrong.  If we didn't provide these
definitions for 10 years we can reasonable expect that applications
defined this stuff locally or used GLIBC headers providing the
protocol definitions.  And as such the only result of this can
be conflict and userland build breakage.

The commit #1 had such a short and terse commit message, that we
cannot even know why such a move and set of new userland exports were
even made.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>