patch 8.2.0587: compiler warning for unused variable

Problem:    Compiler warning for unused variable.
Solution:   Add UNUSED.

src/ex_docmd.c

@@ -4783,7 +4783,7 @@ ends_excmd(int c)
  * to "cmd_start" or has a white space character before it.
  */
     int
-ends_excmd2(char_u *cmd_start, char_u *cmd)
+ends_excmd2(char_u *cmd_start UNUSED, char_u *cmd)
 {
     int c = *cmd;
 

src/version.c

@@ -746,6 +746,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    587,
 /**/
     586,
 /**/