Make the formatting of numbers consistent

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/include/mbedtls/sha256.h b/include/mbedtls/sha256.h
index 1100869..22c2c7d 100644
--- a/include/mbedtls/sha256.h
+++ b/include/mbedtls/sha256.h
@@ -128,7 +128,7 @@
  *                 and have a hash operation started.
  * \param output   The SHA-224 or SHA-256 checksum result.
  *                 This must be a writable buffer of length \c 32 bytes
- *                 for SHA-256, 28 bytes for SHA-224.
+ *                 for SHA-256, \c 28 bytes for SHA-224.
  *
  * \return         \c 0 on success.
  * \return         A negative error code on failure.
@@ -166,7 +166,7 @@
  * \param ilen     The length of the input data in Bytes.
  * \param output   The SHA-224 or SHA-256 checksum result.
  *                 This must be a writable buffer of length \c 32 bytes
- *                 for SHA-256, 28 bytes for SHA-224.
+ *                 for SHA-256, \c 28 bytes for SHA-224.
  * \param is224    Determines which function to use. This must be
  *                 either \c 0 for SHA-256, or \c 1 for SHA-224.
  */
diff --git a/include/mbedtls/sha512.h b/include/mbedtls/sha512.h
index 2852273..ef1fa22 100644
--- a/include/mbedtls/sha512.h
+++ b/include/mbedtls/sha512.h
@@ -135,7 +135,7 @@
  *                 and have a hash operation started.
  * \param output   The SHA-384 or SHA-512 checksum result.
  *                 This must be a writable buffer of length \c 64 bytes
- *                 for SHA-512, 48 bytes for SHA-384.
+ *                 for SHA-512, \c 48 bytes for SHA-384.
  *
  * \return         \c 0 on success.
  * \return         A negative error code on failure.
@@ -173,7 +173,7 @@
  * \param ilen     The length of the input data in Bytes.
  * \param output   The SHA-384 or SHA-512 checksum result.
  *                 This must be a writable buffer of length \c 64 bytes
- *                 for SHA-512, 48 bytes for SHA-384.
+ *                 for SHA-512, \c 48 bytes for SHA-384.
  * \param is384    Determines which function to use. This must be either
  *                 \c 0 for SHA-512, or \c 1 for SHA-384.
  *