Clean up some code using "(expr) ? true : false"

All the code paths simplified here were already using a boolean or used
an expression that led to zero or one, making the extra bits
unnecessary.

Author: Justin Pryzby
Reviewed-by: Tom Lane, Michael Paquier, Peter Smith
Discussion: https://postgr.es/m/20210428182936.GE27406@telsasoft.com

src/backend/utils/adt/tsquery_gist.c

@@ -109,7 +109,7 @@ gtsquery_same(PG_FUNCTION_ARGS)
 	TSQuerySign b = PG_GETARG_TSQUERYSIGN(1);
 	bool	   *result = (bool *) PG_GETARG_POINTER(2);
 
-	*result = (a == b) ? true : false;
+	*result = (a == b);
 
 	PG_RETURN_POINTER(result);
 }