Revert "Allowing for rate < 0 enables rewind playback for eg: RTSP streams."

This reverts commit 76cfaf8a.

New features that are not self-contained and modify src/ are not
welcomed in -bugfix branches without pre-existent consensus.

src/input/input.c

@@ -146,7 +146,6 @@ static input_thread_t *Create( vlc_object_t *p_parent, input_item_t *p_item,
     msg_Dbg( p_input, "Creating an input for '%s'", psz_name);
 
     free( psz_name );
-    psz_name = NULL;
 
     /* Start a timer to mesure how long it takes
      * to launch an input */
@@ -1647,12 +1646,7 @@ static bool Control( input_thread_t *p_input, int i_type,
                 }
             }
 
-            if( (i_rate < 0) && p_input->p->input.b_rescale_ts )
-            {
-                msg_Dbg( p_input, "cannot set negative rate" );
-                i_rate = INPUT_RATE_MIN;
-            }
-            else if( (i_rate > 0) && (i_rate < INPUT_RATE_MIN) )
+            if( i_rate < INPUT_RATE_MIN )
             {
                 msg_Dbg( p_input, "cannot set rate faster" );
                 i_rate = INPUT_RATE_MIN;