patch 8.2.5033: build error with +eval but without +quickfix

Problem:    Build error with +eval but without +quickfix.  Warning for
            uninitialized variable.
Solution:   Adjust #ifdefs. (John Marriott)
diff --git a/src/autocmd.c b/src/autocmd.c
index 06cd028..143891c 100644
--- a/src/autocmd.c
+++ b/src/autocmd.c
@@ -2769,7 +2769,6 @@
     listitem_T	*pli;
     char_u	*cmd = NULL;
     char_u	*end;
-    char_u	*p;
     int		once;
     int		nested;
     int		replace;		// replace the cmd for a group/event
@@ -2937,6 +2936,8 @@
 	}
 	else
 	{
+	    char_u *p = NULL;
+
 	    eli = NULL;
 	    end = NULL;
 	    while (TRUE)