jpeglsdec: Remove write-only variable in ff_jpegls_decode_lse().

libavcodec/jpeglsdec.c:54:9: warning: variable ‘len’ set but not used

libavcodec/jpeglsdec.c

@@ -51,10 +51,9 @@
  */
 int ff_jpegls_decode_lse(MJpegDecodeContext *s)
 {
-    int len, id;
+    int id;
 
-    /* XXX: verify len field validity */
-    len = get_bits(&s->gb, 16);
+    skip_bits(&s->gb, 16);  /* length: FIXME: verify field validity */
     id = get_bits(&s->gb, 8);
 
     switch(id){