[util] Change GetMockTime to return chrono type instead of int

src/util/time.cpp

@@ -53,9 +53,9 @@ void SetMockTime(int64_t nMockTimeIn)
     nMockTime.store(nMockTimeIn, std::memory_order_relaxed);
 }
 
-int64_t GetMockTime()
+std::chrono::seconds GetMockTime()
 {
-    return nMockTime.load(std::memory_order_relaxed);
+    return std::chrono::seconds(nMockTime.load(std::memory_order_relaxed));
 }
 
 int64_t GetTimeMillis()

src/util/time.h

@@ -45,8 +45,9 @@ int64_t GetSystemTimeInSeconds(); // Like GetTime(), but not mockable
 
 /** For testing. Set e.g. with the setmocktime rpc, or -mocktime argument */
 void SetMockTime(int64_t nMockTimeIn);
+
 /** For testing */
-int64_t GetMockTime();
+std::chrono::seconds GetMockTime();
 
 /** Return system time (or mocked time, if set) */
 template <typename T>