pgsql: Move ModifyTableContext->lockmode to UpdateContext

Move ModifyTableContext->lockmode to UpdateContext

Should have been done this way to start with, but I failed to notice
This way we avoid some pointless initialization, and better contains the
variable to exist in the scope where it is really used.

Reviewed-by: Michaël Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/202204191345.qerjy3kxi3eb@alvherre.pgsql

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/a87e75956926f966d90bdd1a6bd495cf59cdc3ad

Modified Files
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src/backend/executor/nodeModifyTable.c | 23 ++++++++---------------
1 file changed, 8 insertions(+), 15 deletions(-)