avformat/crypto.c: remove unnecessary code

Because the newpos variable is set value before use it.
The newpos variable declared at the head partition of crypto_seek.
Make the code clean.

Signed-off-by: Steven Liu <lq@chinaffmpeg.org>

libavformat/crypto.c

@@ -252,21 +252,17 @@ static int64_t crypto_seek(URLContext *h, int64_t pos, int whence)
     case SEEK_CUR:
         pos = pos + c->position;
         break;
-    case SEEK_END: {
-        int64_t newpos = ffurl_seek( c->hd, pos, AVSEEK_SIZE );
+    case SEEK_END:
+        newpos = ffurl_seek( c->hd, pos, AVSEEK_SIZE );
         if (newpos < 0) {
             av_log(h, AV_LOG_ERROR,
                 "Crypto: seek_end - can't get file size (pos=%lld)\r\n", (long long int)pos);
             return newpos;
         }
         pos = newpos - pos;
-        }
-        break;
-    case AVSEEK_SIZE: {
-        int64_t newpos = ffurl_seek( c->hd, pos, AVSEEK_SIZE );
-        return newpos;
-        }
         break;
+    case AVSEEK_SIZE:
+        return ffurl_seek( c->hd, pos, AVSEEK_SIZE );
     default:
         av_log(h, AV_LOG_ERROR,
             "Crypto: no support for seek where 'whence' is %d\r\n", whence);