Fix typos (found by Francesco Pompò)

Manually merging as the pull requests are based on an old branch.

closes #215
closes #216
diff --git a/programs/x509/cert_write.c b/programs/x509/cert_write.c
index 1d287d8..dea852a 100644
--- a/programs/x509/cert_write.c
+++ b/programs/x509/cert_write.c
@@ -40,7 +40,7 @@
 int main( void )
 {
     mbedtls_printf( "MBEDTLS_X509_CRT_WRITE_C and/or MBEDTLS_X509_CRT_PARSE_C and/or "
-            "MBEDTLS_FS_IO and/or MBEDTLS_SHA256_C and_or "
+            "MBEDTLS_FS_IO and/or MBEDTLS_SHA256_C and/or "
             "MBEDTLS_ENTROPY_C and/or MBEDTLS_CTR_DRBG_C and/or "
             "MBEDTLS_ERROR_C not defined.\n");
     return( 0 );
@@ -228,7 +228,6 @@
 
     opt.issuer_crt          = DFL_ISSUER_CRT;
     opt.request_file        = DFL_REQUEST_FILE;
-    opt.request_file        = DFL_REQUEST_FILE;
     opt.subject_key         = DFL_SUBJECT_KEY;
     opt.issuer_key          = DFL_ISSUER_KEY;
     opt.subject_pwd         = DFL_SUBJECT_PWD;