Merge pull request #28185 from asmorkalov:as/static_analysys_fix

Fixed issues identified by PVS Studio #28185

Partially fixes https://github.com/opencv/opencv/issues/28167
Paper: https://pvs-studio.com/en/blog/posts/cpp/1321/

Closed items: N2, N4, N5, N6, N7, N8, N10, N11, N13, N14.

To be continued...

### Pull Request Readiness Checklist

See details at https://github.com/opencv/opencv/wiki/How_to_contribute#making-a-good-pull-request

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

modules/imgcodecs/src/grfmt_exr.cpp

@@ -151,9 +151,6 @@ bool  ExrDecoder::readHeader()
 
     m_file = new InputFile( m_filename.c_str() );
 
-    if( !m_file ) // probably paranoid
-        return false;
-
     m_datawindow = m_file->header().dataWindow();
     m_width = m_datawindow.max.x - m_datawindow.min.x + 1;
     m_height = m_datawindow.max.y - m_datawindow.min.y + 1;