pgsql: Fix comparison of an array of characters with zero to compare wi

Fix comparison of an array of characters with zero to compare with '\0' instead.

Report from Andres Freund.

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/489e6ac5a1a4ca7e4ca7683a86ccd8a5d5e3eb59

Modified Files
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src/backend/utils/adt/pgstatfuncs.c |    4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)