[COMMITTERS] pgsql: Fix typo in comment - Mailing list pgsql-committers

Fix typo in comment

Commit fd31cd265138 renamed the variable to skipping_blocks, but forgot
to update this comment.

Noticed while inspecting code.

Branch
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REL9_6_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/afd56b8521c562f7ed20d04159aa597516d74bf5

Modified Files
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src/backend/commands/vacuumlazy.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)