patch 9.1.0527: inconsistent parameter in Makefiles for Vim executable

Problem:  inconsistent parameter in Makefiles for Vim executable
Solution: consistently use $VIMPROG across all Makefiles
          (RestorerZ)

closes: #15099

Signed-off-by: RestorerZ <restorer@mail2k.ru>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/testdir/Make_mvc.mak b/src/testdir/Make_mvc.mak
index 318cd4a..bd6d1a2 100644
--- a/src/testdir/Make_mvc.mak
+++ b/src/testdir/Make_mvc.mak
@@ -5,9 +5,9 @@
 
 # Testing may be done with a debug build 
 !IF EXIST(..\\vimd.exe) && !EXIST(..\\vim.exe)
-VIMPROG = ..\\vimd
+VIMPROG = ..\\vimd.exe
 !ELSE
-VIMPROG = ..\\vim
+VIMPROG = ..\\vim.exe
 !ENDIF