[SWDEV-538308] CPER CLI 20 limit bug (#499)

The bug was reproduced like this.

In terminal #1, run command:
sudo amd-smi ras --cper --gpu 6 --severity all --folder /tmp/cper_dump --follow 

In terminal #2, inject errors:
while true; do sudo amdgpuras -b 7 -s 1 -m 6 -t 2; sleep 2; done

The terminal #1 starts dumping cper entry information that it captures. After 20 entries have been captured, open terminal #3 and run same command as terminal #1:
sudo amd-smi ras --cper --gpu 6 --severity all --folder /tmp/cper_dump --follow 

From terminal #3, there will be no output, even when terminal #1 continues capturing and printing information.

The fix:

Since we already have more than 20 CPER entries available in the GPU buffer, when we run the command from terminal #3 to start capturing from the beginning and pass 20 buffers to copy entries to, the C++ API returns a code saying there is more data available.

The Python CLI should not treat this as an error, but should continue to print what the API returned.

---------

Signed-off-by: Oosman Saeed <oossaeed@amd.com>

docs/reference/amdsmi-py-api.md

@@ -1279,7 +1279,7 @@ Input parameters:
 * `buffer_size`      pointer to a variable that specifies the size of the cper_data
 * `cursor`           pointer to a variable that will contain the  cursor  for the next call
 
-Output: Dictionary with fields, updated cursor, and a dictionary of the cper_data
+Output: Dictionary with fields, updated cursor, a dictionary of the cper_data, and API status_code
 
 Field | Description
 ---|---
@@ -1297,16 +1297,22 @@ Field | Description
 `flags`            | Reserved flags related to the CPER entry. |
 `persistence_info` | Reserved information related to persistence. |
 
+* `status_code` | Upon successful retrieval of data, status_code will be AMDSMI_STATUS_SUCCESS (0) or AMDSMI_STATUS_MORE_DATA (39) if more data can be retrieve by subsequent call to the `amdsmi_get_gpu_cper_entries` function. In the later case, the input parameter `cursor` should be set to the updated `cursor` that was returned from the previous call.
+
 Exceptions that can be thrown by `amdsmi_get_gpu_cper_entries` function:
 
-* `AmdSmiLibraryException`
+* `AmdSmiLibraryException` with these possible error codes:
+    AMDSMI_STATUS_INVAL
+    AMDSMI_STATUS_UNEXPECTED_SIZE
+    AMDSMI_STATUS_UNEXPECTED_DATA
+    AMDSMI_STATUS_NOT_SUPPORTED
 * `AmdSmiParameterException`
 
 Example:
 
 ```python
 for device in devices:
-    entries, new_cursor, cper_data = amdsmi_get_gpu_cper_entries(device, severity_mask, buffer_size, initial_cursor)
+    entries, new_cursor, cper_data, status_code = amdsmi_get_gpu_cper_entries(device, severity_mask, buffer_size, initial_cursor)
     print("CPER entries for device", device)
     for key, entry in entries.items():
         print("Entry", key)