Enhance LinearSearch with null check for value (#7355)

Added null check for the search value in the find method.

Author: AbhiramSakha

src/main/java/com/thealgorithms/searches/LinearSearch.java

@@ -14,6 +14,7 @@
 package com.thealgorithms.searches;
 
 import com.thealgorithms.devutils.searches.SearchAlgorithm;
+
 /**
  * Linear Search is a simple searching algorithm that checks
  * each element of the array sequentially until the target
@@ -33,7 +34,6 @@
  * @see BinarySearch
  * @see SearchAlgorithm
  */
-
 public class LinearSearch implements SearchAlgorithm {
 
     /**
@@ -45,14 +45,17 @@ public class LinearSearch implements SearchAlgorithm {
      */
     @Override
     public <T extends Comparable<T>> int find(T[] array, T value) {
-        if (array == null || array.length == 0) {
+
+        if (array == null || array.length == 0 || value == null) {
             return -1;
         }
+
         for (int i = 0; i < array.length; i++) {
-            if (array[i].compareTo(value) == 0) {
+            if (array[i] != null && array[i].compareTo(value) == 0) {
                 return i;
             }
         }
+
         return -1;
     }
 }