vacuumdb: Schema-qualify operator in catalog query's WHERE clause.

vacuumdb: Schema-qualify operator in catalog query's WHERE clause.

Commit 1ab67c9dfa, which modified this catalog query so that it
doesn't return temporary relations, forgot to schema-qualify the
operator.  A comment earlier in the function implores us to fully
qualify everything in the query:

	 * Since we execute the constructed query with the default search_path
	 * (which could be unsafe), everything in this query MUST be fully
	 * qualified.

This commit fixes that.  While at it, add a newline for consistency
with surrounding code.

Reviewed-by: Noah Misch
Discussion: https://postgr.es/m/ZwQJYcuPPUsF0reU%40nathan
Backpatch-through: 12