fixed formatting of ximgproc/include/opencv2/segmentation.hpp

[dheer-prog]

Pull Request Readiness Checklist

fixed formatting of ximgproc/include/opencv2/segmentation.hpp in accordance with opencv clang format

-[x] I agree to contribute to the project under Apache 2 License.

• To the best of my knowledge, the proposed patch is not based on a code under GPL or another license that is incompatible with OpenCV
• The PR is proposed to the proper branch
• There is a reference to the original bug report and related work
• There is accuracy test, performance test and test data in opencv_extra repository, if applicable
  Patch to opencv_extra has the same branch name.
• The feature is well documented and sample code can be built with the project CMake