Fix header guard

Author: NlightNFotis

src/goto-harness/function_call_harness_generator.h

@@ -6,8 +6,8 @@ Author: Diffblue Ltd.
 
 \******************************************************************/
 
-#ifndef CPROVER_GOTO_HARNESS_FUNCTION_HARNESS_GENERATOR_H
-#define CPROVER_GOTO_HARNESS_FUNCTION_HARNESS_GENERATOR_H
+#ifndef CPROVER_GOTO_HARNESS_FUNCTION_CALL_HARNESS_GENERATOR_H
+#define CPROVER_GOTO_HARNESS_FUNCTION_CALL_HARNESS_GENERATOR_H
 
 #include <memory>
 #include <string>
@@ -36,4 +36,4 @@ class function_call_harness_generatort : public goto_harness_generatort
   std::unique_ptr<implt> p_impl;
 };
 
-#endif // CPROVER_GOTO_HARNESS_FUNCTION_HARNESS_GENERATOR_H
+#endif // CPROVER_GOTO_HARNESS_FUNCTION_CALL_HARNESS_GENERATOR_H