Update nn_index.h

Correct spelling

Author: trebor8x

src/cpp/flann/algorithms/nn_index.h

@@ -135,7 +135,7 @@ class NNIndex : public IndexBase
 	}
 
 	/**
-	 * Builds th index using using the specified dataset
+	 * Builds the index using the specified dataset
 	 * @param dataset the dataset to use
 	 */
     virtual void buildIndex(const Matrix<ElementType>& dataset)
@@ -482,7 +482,7 @@ class NNIndex : public IndexBase
     /**
      * @brief Perform radius search
      * @param[in] query The query point
-     * @param[out] indices The indinces of the neighbors found within the given radius
+     * @param[out] indices The indices of the neighbors found within the given radius
      * @param[out] dists The distances to the nearest neighbors found
      * @param[in] radius The radius used for search
      * @param[in] params Search parameters
@@ -592,7 +592,7 @@ class NNIndex : public IndexBase
     /**
      * @brief Perform radius search
      * @param[in] query The query point
-     * @param[out] indices The indinces of the neighbors found within the given radius
+     * @param[out] indices The indices of the neighbors found within the given radius
      * @param[out] dists The distances to the nearest neighbors found
      * @param[in] radius The radius used for search
      * @param[in] params Search parameters