Fix typo in comment

Fix typo in program/pkey/ecdh_curve25519.c

Signed-off-by: HowJMay <[email protected]>

ChangeLog.d/fix-typo.txt

@@ -0,0 +1,3 @@
+Bugfix
+   * There is typo in the example code which locates in
+     program/pkey/ecdh_curve25519.c

programs/pkey/ecdh_curve25519.c

@@ -88,7 +88,7 @@ int main( int argc, char *argv[] )
     mbedtls_printf( " ok\n" );
 
     /*
-     * Client: inialize context and generate keypair
+     * Client: initialize context and generate keypair
      */
     mbedtls_printf( "  . Setting up client context..." );
     fflush( stdout );