Assigning rewind to an axis re-enables the default rewind hotkey

Description

When rewind has a default button, but rewind is only bound to an axis, pressing its default button will invoke rewind even if that button is bound to a different action.

Expected behavior

Only explicitly bound actions trigger when a button is pressed. If the menu says rewind is only bound to an axis, only that axis should trigger it.

Actual behavior

See description.

For instance, in my distribution, rewind is bound to Button 6 by default. If I assign rewind to Axis +2 and press button 6 or Axis +2, rewind is invoked.
Re-assigning rewind from an axis to a different button (i.e. button 7) fixes the problem, and button 6 no longer triggers a rewind.

Steps to reproduce the bug

1. Assign rewind button to an axis
2. Press the default rewind hotkey in-game

Version/Commit

You can find this information under Information/System Information

• RetroArch: 1.16.0 f091b5a9e9

Environment information

• OS: unix ARMv8

Start by reproducing the issue in RetroArch 1.16.0 on the reported Unix ARMv8 environment, then trace the input-binding and rewind hotkey handling. Done means assigning rewind to Axis +2 triggers it only from that axis, while the former default button no longer invokes rewind; the payload does not name a source file or test.