[S390] cio: use sense-pgid operation for path verification

Set-pgid operations fail for some device types under z/VM for which
the hypervisor has already set the pgid. Also reserved devices or
changed pgids are not correctly recognized. Fix these problems by
using a combination of sense-pgid and set-pgid and by also accepting
pre-defined pgid settings.

Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

drivers/s390/cio/io_sch.h

@@ -166,7 +166,6 @@ struct ccw_device_private {
 		unsigned int recog_done:1;  /* dev. recog. complete */
 		unsigned int fake_irb:1;    /* deliver faked irb */
 		unsigned int resuming:1;    /* recognition while resume */
-		unsigned int pgid_rdy:1;    /* pgids are ready */
 		unsigned int pgroup:1;	    /* pathgroup is set up */
 		unsigned int mpath:1;	    /* multipathing is set up */
 	} __attribute__((packed)) flags;