Fix comment typo

Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
diff --git a/include/mbedtls/pkcs7.h b/include/mbedtls/pkcs7.h
index 8e4bd48..10a6322 100644
--- a/include/mbedtls/pkcs7.h
+++ b/include/mbedtls/pkcs7.h
@@ -24,7 +24,7 @@
 /**
  * Note: For the time being, this implementation of the PKCS #7 cryptographic
  * message syntax is a partial implementation of RFC 2315.
- * Differences include:#
+ * Differences include:
  *  - The RFC specifies 6 different content types. The only type currently
  *    supported in Mbed TLS is the signed data content type.
  *  - The only supported PKCS #7 Signed Data syntax version is version 1