pgsql: Plug memory leak when reloading config file.

Plug memory leak when reloading config file.

The absolute path to config file was not pfreed. There are probably more
small leaks here and there in the config file reload code and assign hooks,
and in practice no-one reloads the config files frequently enough for it to
be a problem, but this one is trivial enough that might as well fix it.

Backpatch to 9.3 where the leak was introduced.

Branch
------
REL9_3_STABLE

Details
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http://git.postgresql.org/pg/commitdiff/bb604d03abf1402764d384acb1ae36d379965126

Modified Files
--------------
src/backend/utils/misc/guc-file.l |   12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)