patch 8.1.1697: cannot build with MSVC

Problem:    Cannto build with MSVC.
Solution:   Remove the backslashes after the @<< mechanism.
diff --git a/src/Make_mvc.mak b/src/Make_mvc.mak
index e30cecc..4292b91 100644
--- a/src/Make_mvc.mak
+++ b/src/Make_mvc.mak
@@ -1280,9 +1280,9 @@
 		version.c version.h
 	$(CC) $(CFLAGS_OUTDIR) version.c
 	$(link) @<<
-$(LINKARGS1) /dll -out:$(VIMDLLBASE).dll $(OBJ) $(XDIFF_OBJ) $(GUI_OBJ) $(CUI_OBJ) $(OLE_OBJ) \
-$(LUA_OBJ) $(MZSCHEME_OBJ) $(PERL_OBJ) $(PYTHON_OBJ) $(PYTHON3_OBJ) $(RUBY_OBJ) \
-$(TCL_OBJ) $(CSCOPE_OBJ) $(TERM_OBJ) $(SOUND_OBJ) $(NETBEANS_OBJ) $(CHANNEL_OBJ) \
+$(LINKARGS1) /dll -out:$(VIMDLLBASE).dll $(OBJ) $(XDIFF_OBJ) $(GUI_OBJ) $(CUI_OBJ) $(OLE_OBJ)
+$(LUA_OBJ) $(MZSCHEME_OBJ) $(PERL_OBJ) $(PYTHON_OBJ) $(PYTHON3_OBJ) $(RUBY_OBJ)
+$(TCL_OBJ) $(CSCOPE_OBJ) $(TERM_OBJ) $(SOUND_OBJ) $(NETBEANS_OBJ) $(CHANNEL_OBJ)
 $(XPM_OBJ) $(OUTDIR)\version.obj $(LINKARGS2)
 <<
 
@@ -1302,9 +1302,9 @@
 		version.c version.h
 	$(CC) $(CFLAGS_OUTDIR) version.c
 	$(link) @<<
-$(LINKARGS1) /subsystem:$(SUBSYSTEM) -out:$(VIM).exe $(OBJ) $(XDIFF_OBJ) $(GUI_OBJ) $(CUI_OBJ) $(OLE_OBJ) \
-$(LUA_OBJ) $(MZSCHEME_OBJ) $(PERL_OBJ) $(PYTHON_OBJ) $(PYTHON3_OBJ) $(RUBY_OBJ) \
-$(TCL_OBJ) $(CSCOPE_OBJ) $(TERM_OBJ) $(SOUND_OBJ) $(NETBEANS_OBJ) $(CHANNEL_OBJ) \
+$(LINKARGS1) /subsystem:$(SUBSYSTEM) -out:$(VIM).exe $(OBJ) $(XDIFF_OBJ) $(GUI_OBJ) $(CUI_OBJ) $(OLE_OBJ)
+$(LUA_OBJ) $(MZSCHEME_OBJ) $(PERL_OBJ) $(PYTHON_OBJ) $(PYTHON3_OBJ) $(RUBY_OBJ)
+$(TCL_OBJ) $(CSCOPE_OBJ) $(TERM_OBJ) $(SOUND_OBJ) $(NETBEANS_OBJ) $(CHANNEL_OBJ)
 $(XPM_OBJ) $(OUTDIR)\version.obj $(LINKARGS2)
 <<
 	if exist $(VIM).exe.manifest mt.exe -nologo -manifest $(VIM).exe.manifest -updateresource:$(VIM).exe;1