patch 8.0.1537: xxd does not skip NUL lines when using ebcdic

Problem:    Xxd does not skip NUL lines when using ebcdic.
Solution:   Check for a NUL before converting a character for ebcdic. (Tim
            Sell, closes #2668)

src/version.c

@@ -778,6 +778,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1537,
 /**/
     1536,
 /**/

src/xxd/xxd.c

@@ -827,6 +827,8 @@ main(int argc, char *argv[])
 	  for (i = 7; i >= 0; i--)
 	    l[++c] = (e & (1 << i)) ? '1' : '0';
 	}
+      if (e)
+	nonzero++;
       if (ebcdic)
 	e = (e < 64) ? '.' : etoa64[e-64];
       /* When changing this update definition of LLEN above. */
@@ -837,8 +839,6 @@ main(int argc, char *argv[])
 	  (e > 31 && e < 127)
 #endif
 	  ? e : '.';
-      if (e)
-	nonzero++;
       n++;
       if (++p == cols)
 	{