crypto: octeontx - use strscpy_pad in ucode_load_store

crypto: octeontx - use strscpy_pad in ucode_load_store

Instead of zero-initializing the temporary buffer and then copying into
it with strscpy(), use strscpy_pad() to copy the string and zero-pad any
trailing bytes. Drop the explicit size argument to further simplify the
code since strscpy_pad() can determine it automatically when the
destination buffer has a fixed length.

Also use strscpy_pad() to check for string truncation instead of the
hard-coded OTX_CPT_UCODE_NAME_LENGTH.

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>