cli: fix memory leak in volume status detail

gf_cli_status_cbk() never freed the heap strings status.free and
status.total returned by gf_uint64_2human_readable() via gf_asprintf().
Each invocation of `gluster volume status all detail` leaked two
strings per brick reported.

Also fix a pre-existing leak of status.pid_str on error paths — freed
inside the loop but missing from the out: cleanup label.

Since GF_FREE() does not NULL the freed pointer, explicitly NULL all
per-iteration pointers after freeing to prevent double-free when the
normal path falls through to out:.

Fixes: #4292
Signed-off-by: Thales Antunes de Oliveira Barretto <thales.barretto.git@gmail.com>

Author: ThalesBarretto

cli/src/cli-rpc-ops.c

@@ -7601,8 +7601,12 @@ gf_cli_status_cbk(struct rpc_req *req, struct iovec *iov, int count,
             cli_print_brick_status(&status);
         }
 
-        /* Allocatated memory using gf_asprintf*/
         GF_FREE(status.pid_str);
+        status.pid_str = NULL;
+        GF_FREE(status.free);
+        status.free = NULL;
+        GF_FREE(status.total);
+        status.total = NULL;
     }
     cli_out(" ");
 
@@ -7615,6 +7619,9 @@ gf_cli_status_cbk(struct rpc_req *req, struct iovec *iov, int count,
     if (dict)
         dict_unref(dict);
     GF_FREE(status.brick);
+    GF_FREE(status.pid_str);
+    GF_FREE(status.free);
+    GF_FREE(status.total);
     if (local && wipe_local) {
         cli_local_wipe(local);
     }