patch 9.1.0152: Coverity complains about ignoring return value

Problem:  Coverity complains about ignoring return value of win_split()
          (after v9.1.150)
Solution: Check if win_split() failed, add winfixbuf.res to Makefile

src/version.c

@@ -704,6 +704,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    152,
 /**/
     151,
 /**/