pgsql: Improve includes introduced in the replication origins patch.

Improve includes introduced in the replication origins patch.

pg_resetxlog.h contained two superfluous includes, origin.h superfluously
depended on logical.h, and pg_xlogdump's rmgrdesc.h only indirectly
included origin.h.

Backpatch: 9.5, where replication origins were introduced.

Branch
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REL9_5_STABLE

Details
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http://git.postgresql.org/pg/commitdiff/449b13313caf63c2db936cc46d8a25cfcd9a0d04

Modified Files
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src/bin/pg_resetxlog/pg_resetxlog.c |    2 --
src/bin/pg_xlogdump/rmgrdesc.c      |    1 +
src/include/replication/origin.h    |    4 +++-
3 files changed, 4 insertions(+), 3 deletions(-)