Fix stop_postmaster call in get_cluster_version.

[reshke]

stop_postmaster accepts single boolean arg, yet pointer of type ClusterInfo is passed. Remove this, and call stop_postmaster with false argument, resulting in smart (not fast) shutdown. Also remove redundant return at the end on void function.
Introduced as oversight in e20a488.

Fixed with help of coverity report:

** CID 640088:       Null pointer dereferences  (REVERSE_INULL)
/src/bin/pg_upgrade/pg_upgrade.c: 374           in get_cluster_version()


_____________________________________________________________________________________________
*** CID 640088:         Null pointer dereferences  (REVERSE_INULL)
/src/bin/pg_upgrade/pg_upgrade.c: 374             in get_cluster_version()
368     	cluster->dbid = dbid;
369     
370     	PQclear(res);
371     
372     	PQfinish(conn);
373     
>>>     CID 640088:         Null pointer dereferences  (REVERSE_INULL)
>>>     Null-checking "cluster" suggests that it may be null, but it has already been dereferenced on all paths leading to the check.
374     	stop_postmaster(cluster);
375     
376     	return;
377     }
378     
379     #ifdef WIN32

 

[my-ship-it]

Good catch