pgsql: Fix inconsequential fd leak in the new mark_file_as_archived() f

Fix inconsequential fd leak in the new mark_file_as_archived() function.

As every error in mark_file_as_archived() will lead to a failure of
pg_basebackup the FD leak couldn't ever lead to a real problem.  It
seems better to fix the leak anyway though, rather than silence
Coverity, as the usage of the function might get extended or copied at
some point in the future.

Pointed out by Coverity.

Backpatch to 9.2, like the relevant part of the previous patch.

Branch
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REL9_4_STABLE

Details
-------
http://git.postgresql.org/pg/commitdiff/ff7d46b8572ce566230c53e3c937412b3d19d8cf

Modified Files
--------------
src/bin/pg_basebackup/receivelog.c |    3 +++
1 file changed, 3 insertions(+)