doxygen: \p commands misuse - review comments

Apply comments suggested in review.
Signed-off-by: Andrzej Kurek <andrzej.kurek@arm.com>
diff --git a/include/mbedtls/camellia.h b/include/mbedtls/camellia.h
index 540f0fd..8033c13 100644
--- a/include/mbedtls/camellia.h
+++ b/include/mbedtls/camellia.h
@@ -220,7 +220,7 @@
  * *note       Due to the nature of CTR mode, you should use the same
  *             key for both encryption and decryption. In particular, calls
  *             to this function should be preceded by a key-schedule via
- *             mbedtls_camellia_setkey_enc() regardless of whether \c mode
+ *             mbedtls_camellia_setkey_enc() regardless of whether the mode
  *             is #MBEDTLS_CAMELLIA_ENCRYPT or #MBEDTLS_CAMELLIA_DECRYPT.
  *
  * \warning    You must never reuse a nonce value with the same key. Doing so
diff --git a/include/mbedtls/cipher.h b/include/mbedtls/cipher.h
index bdfa7f8..53ef2ad 100644
--- a/include/mbedtls/cipher.h
+++ b/include/mbedtls/cipher.h
@@ -990,7 +990,7 @@
  * \param ctx           The generic cipher context. This must be initialized and
  *                      bound to a key.
  * \param output        The buffer to write data to. This needs to be a writable
- *                      buffer of at least \c block_size Bytes.
+ *                      buffer of at least block_size Bytes.
  * \param olen          The length of the data written to the \p output buffer.
  *                      This may not be \c NULL.
  *
diff --git a/include/mbedtls/ssl.h b/include/mbedtls/ssl.h
index e68ef0e..d3bf80f 100644
--- a/include/mbedtls/ssl.h
+++ b/include/mbedtls/ssl.h
@@ -3124,8 +3124,8 @@
  *
  * \param session  The session structure to be saved.
  * \param buf      The buffer to write the serialized data to. It must be a
- *                 writeable buffer of at least \p olen bytes, or may be \c
- *                 NULL if \p olen is \c 0.
+ *                 writeable buffer of at least \p buf_len bytes, or may be \c
+ *                 NULL if \p buf_len is \c 0.
  * \param buf_len  The number of bytes available for writing in \p buf.
  * \param olen     The size in bytes of the data that has been or would have
  *                 been written. It must point to a valid \c size_t.