Improve error description for invalid scancodes

(cherry picked from commit 56092814f3a1338a219dcab275b22463d6f95182)

src/cocoa_window.m

@@ -1541,7 +1541,7 @@ const char* _glfwPlatformGetScancodeName(int scancode)
     if (scancode < 0 || scancode > 0xff ||
         _glfw.ns.keycodes[scancode] == GLFW_KEY_UNKNOWN)
     {
-        _glfwInputError(GLFW_INVALID_VALUE, "Invalid scancode");
+        _glfwInputError(GLFW_INVALID_VALUE, "Invalid scancode %i", scancode);
         return NULL;
     }
 

src/win32_window.c

@@ -2067,7 +2067,7 @@ const char* _glfwPlatformGetScancodeName(int scancode)
     if (scancode < 0 || scancode > (KF_EXTENDED | 0xff) ||
         _glfw.win32.keycodes[scancode] == GLFW_KEY_UNKNOWN)
     {
-        _glfwInputError(GLFW_INVALID_VALUE, "Invalid scancode");
+        _glfwInputError(GLFW_INVALID_VALUE, "Invalid scancode %i", scancode);
         return NULL;
     }
 

src/x11_window.c

@@ -2886,7 +2886,7 @@ const char* _glfwPlatformGetScancodeName(int scancode)
     if (scancode < 0 || scancode > 0xff ||
         _glfw.x11.keycodes[scancode] == GLFW_KEY_UNKNOWN)
     {
-        _glfwInputError(GLFW_INVALID_VALUE, "Invalid scancode");
+        _glfwInputError(GLFW_INVALID_VALUE, "Invalid scancode %i", scancode);
         return NULL;
     }