Remove errors for gamepad element mismatch

Because there are controllers in the wild using the same hardware ID
despite having different numbers of buttons and axes, an error message
was triggered that was only expected for a corrupted mapping database.

This removes the error for now, in preparation for better error handling
for gamepad mappings overall.

Fixes #1763.

(cherry picked from commit 6876cf8d7e)

README.md

@@ -119,6 +119,8 @@ information on what to include when reporting a bug.
 ## Changelog
 
  - Bugfix: Buffers were swapped at creation on single-buffered windows (#1873)
+ - Bugfix: Gamepad mapping updates could spam `GLFW_INVALID_VALUE` due to
+   incompatible controllers sharing hardware ID (#1763)
  - [Win32] Bugfix: `USE_MSVC_RUNTIME_LIBRARY_DLL` had no effect on CMake 3.15 or
    later (#1783,#1796)
  - [Win32] Bugfix: Compilation with LLVM for Windows failed (#1807,#1824,#1874)

src/input.c

@@ -85,27 +85,15 @@ static _GLFWmapping* findValidMapping(const _GLFWjoystick* js)
         for (i = 0;  i <= GLFW_GAMEPAD_BUTTON_LAST;  i++)
         {
             if (!isValidElementForJoystick(mapping->buttons + i, js))
-            {
-                _glfwInputError(GLFW_INVALID_VALUE,
-                                "Invalid button in gamepad mapping %s (%s)",
-                                mapping->guid,
-                                mapping->name);
                 return NULL;
         }
-        }
 
         for (i = 0;  i <= GLFW_GAMEPAD_AXIS_LAST;  i++)
         {
             if (!isValidElementForJoystick(mapping->axes + i, js))
-            {
-                _glfwInputError(GLFW_INVALID_VALUE,
-                                "Invalid axis in gamepad mapping %s (%s)",
-                                mapping->guid,
-                                mapping->name);
                 return NULL;
         }
     }
-    }
 
     return mapping;
 }