patch 8.0.0452: some macros are in lower case

Problem:    Some macros are in lower case.
Solution:   Make a few more macros upper case.
diff --git a/src/misc2.c b/src/misc2.c
index a6f3c1e..4777129 100644
--- a/src/misc2.c
+++ b/src/misc2.c
@@ -1702,7 +1702,7 @@
     char_u	*q;
 
     q = ptr + STRLEN(ptr);
-    while (--q > ptr && vim_iswhite(q[0]) && q[-1] != '\\' && q[-1] != Ctrl_V)
+    while (--q > ptr && VIM_ISWHITE(q[0]) && q[-1] != '\\' && q[-1] != Ctrl_V)
 	*q = NUL;
 }