LU-13709 utils: 'lfs mkdir -i -1' doesn't work

'lfs mkdir -i -1 -c...' is to create directory on MDTs by space usage,
when stripe count is more than 1, the target MDT list is not correctly
initialized, which will cause command fail.
Signed-off-by: Lai Siyao <lai.siyao@whamcloud.com>
Change-Id: Id4584940cec390a9245e888c96c7873f5afa209e
Reviewed-on: https://review.whamcloud.com/39165

Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>

lustre/utils/lfs.c

@@ -5356,9 +5356,9 @@ static int lfs_setdirstripe(int argc, char **argv)
 			}
 
 			if (auto_distributed) {
-				int r;
 				int nr = MAX(param->lsp_stripe_count,
 					     lsb->sb_count / 2);
+				int r;
 
 				/* don't use server whose usage is above 90% */
 				while (nr != param->lsp_stripe_count &&
@@ -5374,11 +5374,15 @@ static int lfs_setdirstripe(int argc, char **argv)
 					lsb->sb_buf[r].sd_index;
 				if (param->lsp_stripe_count > 1) {
 					int i = 0;
+					int j;
 
 					param->lsp_is_specific = true;
-					for (; i < param->lsp_stripe_count; i++)
-						param->lsp_tgts[(i + r) % nr] =
-							lsb->sb_buf[i].sd_index;
+					for (; i < param->lsp_stripe_count;
+					     i++) {
+						j = (i + r) % nr;
+						param->lsp_tgts[i] =
+							lsb->sb_buf[j].sd_index;
+					}
 				}
 			}