Merge pull request opencv#18519 from alalek:fix_javadoc

Author: alalek

modules/calib3d/include/opencv2/calib3d.hpp

@@ -2163,7 +2163,7 @@ final fundamental matrix. It can be set to something like 1-3, depending on the
 point localization, image resolution, and the image noise.
 @param confidence Parameter used for the RANSAC and LMedS methods only. It specifies a desirable level
 of confidence (probability) that the estimated matrix is correct.
-@param mask
+@param[out] mask optional output mask
 @param maxIters The maximum number of robust method iterations.
 
 The epipolar geometry is described by the following equation:

modules/java/generator/gen_java.py

@@ -769,6 +769,7 @@ def gen_func(self, ci, fi, prop_name=''):
                             inCode = True
                         if "</code>" in line:
                             inCode = False
+                        line = line.replace('@result ', '@return ')  # @result is valid in Doxygen, but invalid in Javadoc
                         if "@return " in line:
                             returnTag = True