staging: lustre: osc: remove handling cl_avail_grant less than zero

Earlier cl_avail_grant was changed to an unsigned int. Juila
Lawall reported for the upstream client the following which
affects the Intel branch as well:

drivers/staging/lustre/lustre/osc/osc_request.c:1045:5-24: WARNING: Unsigned
expression compared with zero: cli -> cl_avail_grant < 0

Since cl_avail_grant can never be negative we can remove the
code handling the negative value case.
Signed-off-by: James Simmons <uja.ornl@yahoo.com>
Intel-bug-id: LU-8697 https://jira.hpdd.intel.com/browse/LU-6303
Reviewed-on: http://review.whamcloud.com/23155Reviewed-by: Fan Yong <fan.yong@intel.com>
Reviewed-by: Frank Zago <fzago@cray.com>
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/lustre/lustre/osc/osc_request.c

@@ -801,16 +801,6 @@ static void osc_init_grant(struct client_obd *cli, struct obd_connect_data *ocd)
 		cli->cl_avail_grant = ocd->ocd_grant -
 				      (cli->cl_dirty_pages << PAGE_SHIFT);
 
-	if (cli->cl_avail_grant < 0) {
-		CWARN("%s: available grant < 0: avail/ocd/dirty %ld/%u/%ld\n",
-		      cli->cl_import->imp_obd->obd_name, cli->cl_avail_grant,
-		      ocd->ocd_grant, cli->cl_dirty_pages << PAGE_SHIFT);
-		/* workaround for servers which do not have the patch from
-		 * LU-2679
-		 */
-		cli->cl_avail_grant = ocd->ocd_grant;
-	}
-
 	/* determine the appropriate chunk size used by osc_extent. */
 	cli->cl_chunkbits = max_t(int, PAGE_SHIFT, ocd->ocd_blocksize);
 	spin_unlock(&cli->cl_loi_list_lock);