read returns error value to timeout

[rlm2002]

Java_com_wolfssl_WolfSSLSession_read() returns error value of socketPoll() if encountered. Originally breaks and returns size.

[cconlon]

We can't return directly here since we need to drop down and call ReleaseByteArrayElements() below the while loop.

We can do:

size = ret;
break;

But, since that's the same as the "else" block below it, we should consolodate the two together. I recommend one "else" block that does the above, but adjust the code comment inside the else to include that Java will throw SocketTimeoutException or SocketException in the case of WOLFJNI_IO_EVENT_TIMEOUT, WOLFJNI_IO_EVENT_FD_CLOSED, WOLFJNI_IO_EVENT_ERROR, WOLFJNI_IO_EVENT_POLLHUP, and WOLFJNI_IO_EVENT_FAIL.