Grow: close file descriptor earlier to avoid "still in use" when stopping

Close fd2 as soon as it is no longer needed, before calling
Grow_continue(). Otherwise, we won't be able to stop an array with
external metadata during reshape, because mdadm running in background
will be keeping it open.

Signed-off-by: Artur Paszkiewicz <artur.paszkiewicz@intel.com>
Signed-off-by: Pawel Baldysiak <pawel.baldysiak@intel.com>
Signed-off-by: NeilBrown <neilb@suse.com>

Grow.c

@@ -4885,6 +4885,9 @@ int Grow_continue_command(char *devname, int fd,
 
 		sysfs_init(content, fd2, mdstat->devnm);
 
+		close(fd2);
+		fd2 = -1;
+
 		/* start mdmon in case it is not running
 		 */
 		if (!mdmon_running(container))