imsm: imsm_read_serial check for zero-length response

VMWare virtual disks successfully run the inquiry but return a zero response.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>

super-intel.c

@@ -1415,6 +1415,13 @@ static int imsm_read_serial(int fd, char *devname,
 
 	/* trim leading whitespace */
 	rsp_len = scsi_serial[3];
+	if (!rsp_len) {
+		if (devname)
+			fprintf(stderr,
+				Name ": Failed to retrieve serial for %s\n",
+				devname);
+		return 2;
+	}
 	rsp_buf = (char *) &scsi_serial[4];
 	c = rsp_buf;
 	while (isspace(*c))