Fix typos in code.

Resolves #2775.

Author: sujl95

src/main/java/org/springframework/data/jpa/mapping/JpaMetamodelMappingContext.java

@@ -196,7 +196,7 @@ private Metamodel getMetamodelFor(Class<?> type) {
 				} catch (IllegalArgumentException o_O) {
 
 					// Fall back to inspect *all* managed types manually as Metamodel.managedType(…) only
-					// returns for entities, embeddables and managed supperclasses.
+					// returns for entities, embeddables and managed superclasses.
 
 					for (ManagedType<?> managedType : model.getManagedTypes()) {
 						if (type.equals(managedType.getJavaType())) {

src/main/java/org/springframework/data/jpa/support/MergingPersistenceUnitManager.java

@@ -27,7 +27,7 @@
 
 /**
  * Extends {@link DefaultPersistenceUnitManager} to merge configurations of one persistence unit residing in multiple
- * {@code persistence.xml} files into one. This is necessary to allow the declaration of entities in seperate modules.
+ * {@code persistence.xml} files into one. This is necessary to allow the declaration of entities in separate modules.
  *
  * @author Oliver Gierke
  * @link https://github.com/spring-projects/spring-framework/issues/7287