patch 9.1.1246: coverity complains about some changes in v9.1.1243

Problem:  coverity complains about some changes in v9.1.1243
Solution: remove duplicate code in diff_find_changed() (Yee Cheng Chin)

closes: #16988

Signed-off-by: Yee Cheng Chin <ychin.git@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

src/diff.c

@@ -3598,7 +3598,6 @@ diff_find_change(
 
 	// Create a mock diffline struct. We always only have one so no need to
 	// allocate memory.
-	idx = diff_buf_idx(wp->w_buffer);;
 	CLEAR_FIELD(simple_diffline_change);
 	diffline->changes = &simple_diffline_change;
 	diffline->num_changes = 1;

src/version.c

@@ -704,6 +704,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1246,
 /**/
     1245,
 /**/