fix(module: carousel): fix vertical mode width error.

[Guoyuanqiang]

PR Checklist

Please check if your PR fulfills the following requirements:

• The commit message follows our guidelines: https://github.com/NG-ZORRO/ng-zorro-antd-mobile/blob/master/CONTRIBUTING.md#commit
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

[x] Bugfix
[ ] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[ ] Build related changes
[ ] CI related changes
[ ] Documentation content changes
[ ] Application (the showcase website) / infrastructure changes
[ ] Other... Please describe:

What is the current behavior?

Issue Number: N/A

What is the new behavior?

Does this PR introduce a breaking change?

[ ] Yes
[ ] No

Other information

[codecov]

Codecov Report

Merging #477 into master will increase coverage by <.01%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #477      +/-   ##
==========================================
+ Coverage   87.51%   87.52%   +<.01%     
==========================================
  Files         270      270              
  Lines        7579     7581       +2     
  Branches     1078     1079       +1     
==========================================
+ Hits         6633     6635       +2     
  Misses        530      530              
  Partials      416      416

Impacted Files	Coverage Δ
components/carousel/carousel.component.ts	66.32% <100%> (+0.11%)	⬆️
...arousel/carousel-slide/carousel-slide.component.ts	100% <100%> (ø)	⬆️

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