3744 zfs shouldn't ignore errors unmounting snapshots
Submitted by:   Will Andrews <willa@spectralogic.com>
Reviewed by:    Matthew Ahrens <mahrens@delphix.com>

@@ -431,11 +431,11 @@
         if (error == 0) {
                 char name[MAXNAMELEN];
                 dsl_dataset_name(ds, name);
                 dsl_dataset_rele(ds, FTAG);
                 dsl_pool_config_exit(dp, FTAG);
-                zfs_unmount_snap(name);
+                (void) zfs_unmount_snap(name);
         } else {
                 dsl_pool_config_exit(dp, FTAG);
         }
 #endif