patch 8.2.5088: value of cmod_verbose is a bit complicated to use

Problem:    Value of cmod_verbose is a bit complicated to use.
Solution:   Use zero for not set, value + 1 when set. (closes #10564)
diff --git a/src/globals.h b/src/globals.h
index 7100dcd..63377af 100644
--- a/src/globals.h
+++ b/src/globals.h
@@ -1291,7 +1291,7 @@
 
 EXTERN int	postponed_split INIT(= 0);  // for CTRL-W CTRL-] command
 EXTERN int	postponed_split_flags INIT(= 0);  // args for win_split()
-EXTERN int	postponed_split_tab INIT(= 0);  // cmdmod.tab
+EXTERN int	postponed_split_tab INIT(= 0);  // cmdmod.cmod_tab
 #ifdef FEAT_QUICKFIX
 EXTERN int	g_do_tagpreview INIT(= 0);  // for tag preview commands:
 					    // height of preview window