Revert "Skip checking on maximum fragment length during handshake"

This reverts commit 419f841511e0e26e846b6d512094fd935b03ef2d.

Signed-off-by: Waleed Elmelegy <waleed.elmelegy@arm.com>
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 4d6b958..419185c 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -3472,10 +3472,6 @@
 {
     size_t max_len = MBEDTLS_SSL_OUT_CONTENT_LEN;
 
-    if (ssl == NULL || ssl->conf == NULL) {
-        return max_len;
-    }
-
 #if !defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH) && \
     !defined(MBEDTLS_SSL_RECORD_SIZE_LIMIT) && \
     !defined(MBEDTLS_SSL_PROTO_DTLS)
@@ -3483,14 +3479,10 @@
 #endif
 
 #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
-    /* MbedTLS currently does not support maximum fragment length
-       during handshake so we skip it for now. */
-    if (ssl->state == MBEDTLS_SSL_HANDSHAKE_OVER) {
-        const size_t mfl = mbedtls_ssl_get_output_max_frag_len(ssl);
+    const size_t mfl = mbedtls_ssl_get_output_max_frag_len(ssl);
 
-        if (max_len > mfl) {
-            max_len = mfl;
-        }
+    if (max_len > mfl) {
+        max_len = mfl;
     }
 #endif