patch 8.1.0770: inconsistent use of ELAPSED_FUNC

Problem:    Inconsistent use of ELAPSED_FUNC.
Solution:   Consistently use ELAPSED_FUNC.  Also turn ELAPSED_TYPE into a
            typedef. (Ozaki Kiichi, closes #3815)
diff --git a/src/vim.h b/src/vim.h
index b11f1cc..9ae3b30 100644
--- a/src/vim.h
+++ b/src/vim.h
@@ -2625,17 +2625,15 @@
 # define ELAPSED_TIMEVAL
 # define ELAPSED_INIT(v) gettimeofday(&v, NULL)
 # define ELAPSED_FUNC(v) elapsed(&v)
-# define ELAPSED_TYPE struct timeval
-    long elapsed(struct timeval *start_tv);
-#else
-# if defined(WIN32)
-#  define ELAPSED_TICKCOUNT
-#  define ELAPSED_INIT(v) v = GetTickCount()
-#  define ELAPSED_FUNC(v) elapsed(v)
-#  define ELAPSED_TYPE DWORD
-#   ifndef PROTO
-     long elapsed(DWORD start_tick);
-#   endif
+typedef struct timeval elapsed_T;
+long elapsed(struct timeval *start_tv);
+#elif defined(WIN32)
+# define ELAPSED_TICKCOUNT
+# define ELAPSED_INIT(v) v = GetTickCount()
+# define ELAPSED_FUNC(v) elapsed(v)
+typedef DWORD elapsed_T;
+# ifndef PROTO
+long elapsed(DWORD start_tick);
 # endif
 #endif