Fix for CID 299627 memory leak on error case

Author: JacobBarthelmeh

src/ssl.c

@@ -37181,6 +37181,8 @@ PKCS7* wolfSSL_SMIME_read_PKCS7(WOLFSSL_BIO* in,
     XFREE(section, NULL, DYNAMIC_TYPE_PKCS7);
     if (canonSection != NULL)
         XFREE(canonSection, NULL, DYNAMIC_TYPE_PKCS7);
+    if (cannonLine != NULL)
+        XFREE(canonLine, NULL, DYNAMIC_TYPE_PKCS7);
     if (bcont) {
         wolfSSL_BIO_free(*bcont);
         *bcont = NULL; /* reset 'bcount' pointer to NULL on failure */