nl-cache: Remove the max limit for nl-cache-limit and nl-cache-timeout

The max limit is better unset when arbitrary. Otherwise in the future
if max has to be changed, it can break backward compatility.

>Reviewed-on: https://review.gluster.org/17261
>Smoke: Gluster Build System <jenkins@build.gluster.org>
>NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
>CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
>Reviewed-by: Jeff Darcy <jeff@pl.atyp.us>
>(cherry picked from commit 64f41b9)

Change-Id: I4337a3789a2d0d5cc8e2bf687a22536c97608461
BUG: 1453152
Signed-off-by: Poornima G <pgurusid@redhat.com>
Reviewed-on: https://review.gluster.org/17400
Smoke: Gluster Build System <jenkins@build.gluster.org>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
Reviewed-by: Shyamsundar Ranganathan <srangana@redhat.com>

xlators/performance/nl-cache/src/nl-cache.c

@@ -765,15 +765,13 @@ struct volume_options options[] = {
         { .key = {"nl-cache-limit"},
           .type = GF_OPTION_TYPE_SIZET,
           .min = 0,
-          .max = 100 * GF_UNIT_MB,
           .default_value = "131072",
           .description = "the value over which caching will be disabled for"
                          "a while and the cache is cleared based on LRU",
         },
         { .key = {"nl-cache-timeout"},
           .type = GF_OPTION_TYPE_TIME,
           .min = 0,
-          .max = 1 * GF_DAY_IN_SECONDS,
           .default_value = "60",
           .description = "Time period after which cache has to be refreshed",
         },