cache: disallow stripes/size for cache pool

ATM allocation can't handle stripping and cache pool allocation.
It's not yet even clear what should be actually result.
Until resolved, disable this option (it's been coredumping
inside allocation anyway).

WHATS_NEW

@@ -1,5 +1,6 @@
 Version 2.02.131 - 
 =====================================
+  Disallow usage of --stripe and --stripsize when creating cache pool.
   Warn user when caching raid or thin pool data LV.
   When layering LV, move LV flags with segments.
   Ignore persistent cache if configuration changed. (2.02.127)

tools/lvcreate.c

@@ -770,7 +770,8 @@ static int _lvcreate_params(struct cmd_context *cmd,
 					    CACHE_POOL_ARGS,
 					    LVCREATE_ARGS,
 					    POOL_ARGS,
-					    SIZE_ARGS,
+					    extents_ARG,
+					    size_ARG,
 					    cache_ARG,
 					    chunksize_ARG,
 					    -1))
@@ -1096,6 +1097,8 @@ static int _determine_cache_argument(struct volume_group *vg,
 		}
 		/* FIXME How to handle skip flag? */
 		if (arg_from_list_is_set(cmd, "is unsupported with cache conversion",
+					 stripes_ARG,
+					 stripesize_ARG,
 					 setactivationskip_ARG,
 					 ignoreactivationskip_ARG,
 					 -1))