Restore behavior on platforms where CRIU is supported but not in use

This PR aims to fix an issue on how to read random data and
get random bytes on platforms where CRIU is supported, but
not in use by enabling it via a --enable-criu-support JVM
option.

src/java.base/unix/classes/sun/security/provider/NativePRNG.java

@@ -25,7 +25,7 @@
 
 /*
  * ===========================================================================
- * (c) Copyright IBM Corp. 2022, 2023 All Rights Reserved
+ * (c) Copyright IBM Corp. 2022, 2024 All Rights Reserved
  * ===========================================================================
  */
 
@@ -506,8 +506,9 @@ private static void readFully(InputStream in, byte[] data, Variant variant)
  if (in.readNBytes(data, 0, len) < len) {
  throw new IOException("Could not read from file(s)");
  }
+ return;
  }
- /*[ELSE] CRIU_SUPPORT */
+ /*[ENDIF] CRIU_SUPPORT */
  int ofs = 0;
  while (len > 0) {
  int k = in.read(data, ofs, len);
@@ -520,7 +521,6 @@ private static void readFully(InputStream in, byte[] data, Variant variant)
  if (len > 0) {
  throw new IOException("Could not read from file(s)");
  }
- /*[ENDIF] CRIU_SUPPORT */
  }
 
  // get true random bytes, just read from "seed"
@@ -631,8 +631,9 @@ private void implNextBytes(byte[] data) {
  for (int i = 0; i < data.length; i++) {
  data[i] ^= rawData[i];
  }
+ return;
  }
- /*[ELSE] CRIU_SUPPORT */
+ /*[ENDIF] CRIU_SUPPORT */
  int data_len = data.length;
  int ofs = 0;
  int len;
@@ -662,7 +663,6 @@ private void implNextBytes(byte[] data) {
  }
  data_len -= len;
  }
- /*[ENDIF] CRIU_SUPPORT */
  } catch (IOException e){
  throw new ProviderException("nextBytes() failed", e);
  }