[BUG] when ucp listener enabled we bind 16 times always

[abellina]

Noticed this when looking at more error handling using UCX's UCPListener:

[1621604466.240135] [test-server:9155 :0]   tcp_listener.c:134  UCX  DEBUG created a TCP listener 0x7f48d00950c0 on cm 0x7f48d00801f0 with fd: 389 listening on 192.168.50.80:36221
[1621604466.240202] [test-server:9155 :0]   tcp_listener.c:134  UCX  DEBUG created a TCP listener 0x7f48d0095890 on cm 0x7f48d00801f0 with fd: 390 listening on 192.168.50.80:36222
[1621604466.240257] [test-server:9155 :0]   tcp_listener.c:134  UCX  DEBUG created a TCP listener 0x7f48d007d2b0 on cm 0x7f48d00801f0 with fd: 391 listening on 192.168.50.80:36223
[1621604466.240289] [test-server:9155 :0]   tcp_listener.c:134  UCX  DEBUG created a TCP listener 0x7f48d007d280 on cm 0x7f48d00801f0 with fd: 392 listening on 192.168.50.80:36224
[1621604466.240320] [test-server:9155 :0]   tcp_listener.c:134  UCX  DEBUG created a TCP listener 0x7f48d0095ce0 on cm 0x7f48d00801f0 with fd: 393 listening on 192.168.50.80:36225
[1621604466.240351] [test-server:9155 :0]   tcp_listener.c:134  UCX  DEBUG created a TCP listener 0x7f48d0095e30 on cm 0x7f48d00801f0 with fd: 394 listening on 192.168.50.80:36226
[1621604466.240384] [test-server:9155 :0]   tcp_listener.c:134  UCX  DEBUG created a TCP listener 0x7f48d0096120 on cm 0x7f48d00801f0 with fd: 395 listening on 192.168.50.80:36227
[1621604466.240415] [test-server:9155 :0]   tcp_listener.c:134  UCX  DEBUG created a TCP listener 0x7f48d0096270 on cm 0x7f48d00801f0 with fd: 396 listening on 192.168.50.80:36228
[1621604466.240446] [test-server:9155 :0]   tcp_listener.c:134  UCX  DEBUG created a TCP listener 0x7f48d00963c0 on cm 0x7f48d00801f0 with fd: 397 listening on 192.168.50.80:36229
[1621604466.240482] [test-server:9155 :0]   tcp_listener.c:134  UCX  DEBUG created a TCP listener 0x7f48d0096510 on cm 0x7f48d00801f0 with fd: 398 listening on 192.168.50.80:36230
[1621604466.240513] [test-server:9155 :0]   tcp_listener.c:134  UCX  DEBUG created a TCP listener 0x7f48d0096660 on cm 0x7f48d00801f0 with fd: 399 listening on 192.168.50.80:36231
[1621604466.240543] [test-server:9155 :0]   tcp_listener.c:134  UCX  DEBUG created a TCP listener 0x7f48d00967b0 on cm 0x7f48d00801f0 with fd: 400 listening on 192.168.50.80:36232
[1621604466.240573] [test-server:9155 :0]   tcp_listener.c:134  UCX  DEBUG created a TCP listener 0x7f48d0096900 on cm 0x7f48d00801f0 with fd: 401 listening on 192.168.50.80:36233
[1621604466.240604] [test-server:9155 :0]   tcp_listener.c:134  UCX  DEBUG created a TCP listener 0x7f48d0096a50 on cm 0x7f48d00801f0 with fd: 402 listening on 192.168.50.80:36234
[1621604466.240636] [test-server:9155 :0]   tcp_listener.c:134  UCX  DEBUG created a TCP listener 0x7f48d0096ba0 on cm 0x7f48d00801f0 with fd: 403 listening on 192.168.50.80:36235
[1621604466.240666] [test-server:9155 :0]   tcp_listener.c:134  UCX  DEBUG created a TCP listener 0x7f48d0096cf0 on cm 0x7f48d00801f0 with fd: 404 listening on 192.168.50.80:3623

The 16 binds are because we are not exiting early here: https://github.com/NVIDIA/spark-rapids/blob/branch-21.06/shuffle-plugin/src/main/scala/com/nvidia/spark/rapids/shuffle/ucx/UCX.scala#L209

Fix coming.