[fix][cli] Fix error messages in CmdNameSpaces and CmdTopics

[JooHyukKim]

Motivation

Fixes error messages CmdNameSpaces and CmdTopics that describe opposite of what really happens.

Modifications

Same as title.

Verifying this change

Does this pull request potentially affect one of the following parts:

If the box was checked, please highlight the changes

• Dependencies (add or upgrade a dependency)
• The public API
• The schema
• The default values of configurations
• The threading model
• The binary protocol
• The REST endpoints
• The admin CLI options
• The metrics
• Anything that affects deployment

Documentation

• doc
• doc-required
• doc-not-needed
• doc-complete

Matching PR in forked repository

PR in forked repository:

[codecov-commenter]

Codecov Report

Merging #20701 (fcaa60e) into master (c5237ea) will decrease coverage by 0.04%.
The diff coverage is 0.00%.

@@             Coverage Diff              @@
##             master   #20701      +/-   ##
============================================
- Coverage     73.13%   73.10%   -0.04%     
+ Complexity    32101    32089      -12     
============================================
  Files          1871     1871              
  Lines        138982   138982              
  Branches      15283    15283              
============================================
- Hits         101651   101599      -52     
- Misses        29280    29319      +39     
- Partials       8051     8064      +13     

Flag	Coverage Δ
inttests	24.11% <0.00%> (-0.10%)	⬇️
systests	24.98% <0.00%> (-0.15%)	⬇️
unittests	72.37% <0.00%> (-0.02%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
...ava/org/apache/pulsar/admin/cli/CmdNamespaces.java	76.17% <0.00%> (ø)
...in/java/org/apache/pulsar/admin/cli/CmdTopics.java	78.94% <0.00%> (ø)

... and 77 files with indirect coverage changes

[tisonkun]

Merging...

Thank you!