oem: meta: stabilise decode_oem_meta_file_io_req()

Use of decode_oem_meta_file_io_req() is demonstrated in:

67050: Support OEM-META write file request for post code history
https://gerrit.openbmc.org/c/openbmc/pldm/+/67050

Change-Id: I03cfd68f279f9bfdf515ca4302561ca0464c75cc
Signed-off-by: Andrew Jeffery <andrew@codeconstruct.com.au>
diff --git a/src/oem/meta/file_io.c b/src/oem/meta/file_io.c
index 6662e8f..ab6c7a6 100644
--- a/src/oem/meta/file_io.c
+++ b/src/oem/meta/file_io.c
@@ -6,7 +6,7 @@
 #include "msgbuf.h"
 
 #define PLDM_OEM_META_DECODE_WRITE_FILE_IO_MIN_SIZE 6
-LIBPLDM_ABI_TESTING
+LIBPLDM_ABI_STABLE
 int decode_oem_meta_file_io_req(const struct pldm_msg *msg,
 				size_t payload_length, uint8_t *file_handle,
 				uint32_t *length, uint8_t *data)