[SCSI] Make host_no an unsigned int

Daniel Debonzi reports that he has managed to wrap host_no.  Increasing
the number of host numbers available to 32-bit from 16-bit allows the
problem to be evaded for another hundred years.

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

include/scsi/scsi_host.h

@@ -547,7 +547,7 @@ struct Scsi_Host {
 	unsigned int host_failed;	   /* commands that failed. */
 	unsigned int host_eh_scheduled;    /* EH scheduled without command */
 
-	unsigned short host_no;  /* Used for IOCTL_GET_IDLUN, /proc/scsi et al. */
+	unsigned int host_no;  /* Used for IOCTL_GET_IDLUN, /proc/scsi et al. */
 	int resetting; /* if set, it means that last_reset is a valid value */
 	unsigned long last_reset;