Dont check for null before instanceof.

Instanceof already performs the check, so it's a duplicate.

src/main/java/org/orekit/files/ccsds/utils/lexical/XmlLexicalAnalyzer.java

@@ -79,7 +79,7 @@ class XmlLexicalAnalyzer implements LexicalAnalyzer {
 
         } catch (SAXException se) {
             final OrekitException oe;
-            if (se.getException() != null && se.getException() instanceof OrekitException) {
+            if (se.getException() instanceof OrekitException) {
                 oe = (OrekitException) se.getException();
             } else {
                 oe = new OrekitException(se, new DummyLocalizable(se.getMessage()));

src/main/java/org/orekit/frames/EOPHistory.java

@@ -168,7 +168,7 @@ public class EOPHistory implements Serializable {
      * @return true if the instance uses interpolation on tidal corrections
      */
     public boolean usesInterpolation() {
-        return tidalCorrection != null && tidalCorrection instanceof CachedCorrection;
+        return tidalCorrection instanceof CachedCorrection;
     }
 
     /** Get the IERS conventions to which these EOP apply.

src/main/java/org/orekit/frames/RapidDataAndPredictionXMLLoader.java

@@ -131,7 +131,7 @@ class RapidDataAndPredictionXMLLoader extends AbstractEopLoader
                 return history;
 
             } catch (SAXException se) {
-                if (se.getCause() != null && se.getCause() instanceof OrekitException) {
+                if (se.getCause() instanceof OrekitException) {
                     throw (OrekitException) se.getCause();
                 }
                 throw new OrekitException(se, LocalizedCoreFormats.SIMPLE_MESSAGE, se.getMessage());

src/main/java/org/orekit/propagation/semianalytical/dsst/utilities/JacobiPolynomials.java

@@ -264,7 +264,7 @@ public class JacobiPolynomials {
         @Override
         public boolean equals(final Object key) {
 
-            if (key == null || !(key instanceof JacobiKey)) {
+            if (!(key instanceof JacobiKey)) {
                 return false;
             }
 

src/main/java/org/orekit/time/AbsoluteDate.java

@@ -1192,7 +1192,7 @@ public class AbsoluteDate
             return true;
         }
 
-        if (date != null && date instanceof AbsoluteDate) {
+        if (date instanceof AbsoluteDate) {
             return durationFrom((AbsoluteDate) date) == 0;
         }
 

src/main/java/org/orekit/time/FieldAbsoluteDate.java

@@ -1365,7 +1365,7 @@ public class FieldAbsoluteDate<T extends RealFieldElement<T>>
             return true;
         }
 
-        if (date != null && date instanceof FieldAbsoluteDate) {
+        if (date instanceof FieldAbsoluteDate) {
             return durationFrom((FieldAbsoluteDate<T>) date).getReal() == 0.0;
         }