[pgpool-committers: 9527] pgpool: Fix covery warning.

[Tatsuo Ishii]

Fix covery warning.

Fix query cache module assigned time_t value to int32 variable. Change
the variable type to int64. Per Coverity.  Also use difftime() to
calculate time_t difference. This is a recommended practice.
https://www.jpcert.or.jp/sc-rules/c-msc05-c.html

Branch
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V4_3_STABLE

Details
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https://git.postgresql.org/gitweb?p=pgpool2.git;a=commitdiff;h=a99fa4fb6b380a3658408908a69025dd84dfb262

Modified Files
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src/include/query_cache/pool_memqcache.h | 2 +-
src/query_cache/pool_memqcache.c         | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)