Fix typo introduced in 6185c97

Reported-by: Jian He <jian.universality@gmail.com>
Discussion: https://postgr.es/m/CACJufxGHiU0p0usjh5hnR0_ByZn4tq1FC3eKAtrQgJeKU6W9kw@mail.gmail.com

Author: amitlan

src/backend/parser/parse_expr.c

@@ -4334,7 +4334,7 @@ transformJsonFuncExpr(ParseState *pstate, JsonFuncExpr *func)
 				 parser_errposition(pstate, exprLocation(path_spec))));
 	jsexpr->path_spec = path_spec;
 
-	/* Transform and coerce the PASSING arguments to to jsonb. */
+	/* Transform and coerce the PASSING arguments to jsonb. */
 	transformJsonPassingArgs(pstate, func_name,
 							 JS_FORMAT_JSONB,
 							 func->passing,