Fix javadocs comments

Author: thomasmueller

fastfilter/src/main/java/com/github/fastfilter/Filter.java

@@ -59,6 +59,7 @@ default void remove(long key) {
     /**
      * Get the number of set bits. This should be 0 for an empty filter.
      *
+     * @return the number of bits
      */
     default long cardinality() {
         return -1;

fastfilter/src/main/java/com/github/fastfilter/bloom/count/Select.java

@@ -142,7 +142,7 @@ public class Select {
 
     /**
      * Get the position of the n-th bit. Position 0 is the first bit (e.g. x = 1).
-     * Undefined if n >= number of bits in x.
+     * Undefined if n is larger or equal the number of bits in x.
      *
      * @param x the value
      * @param n the bit