cli: fix memory leak in volume status detail (#4292)

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.  The reporter's ASan trace confirms 144
bytes leaked in 4 allocations (2 calls x 2 bricks).

The other string fields in cli_volume_status_t (fs_name, mount_options,
device, inode_size) are borrowed pointers from dict_get_str() — they
are released by dict_unref() at the out: label and must NOT be freed
per-field.

Also fix a pre-existing leak of status.pid_str on the
cli_get_detail_status() error path: if cli_get_detail_status() fails
(goto out after line 7597), pid_str is already allocated via
gf_asprintf() but the out: label never freed it.  The gf_asprintf
failure path at line 7592 cannot leak pid_str because gf_vasprintf()
does not write *string_ptr on allocation failure — the pointer stays
NULL from the {0} initializer.

Since GF_FREE() does not NULL the freed pointer, all per-iteration
pointers are explicitly NULLed 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);
     }