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/if_cscope.c b/src/if_cscope.c
index 5b38498..7a53323 100644
--- a/src/if_cscope.c
+++ b/src/if_cscope.c
@@ -781,7 +781,7 @@
      * they may want to use the leading white space. */
     pat = pattern;
     if (search != 4 && search != 6)
-	while vim_iswhite(*pat)
+	while VIM_ISWHITE(*pat)
 	    ++pat;
 
     if ((cmd = (char *)alloc((unsigned)(strlen(pat) + 2))) == NULL)