ANDROID: usb: gadget: configfs: Move CONFIGFS_UEVENT #endif

Move the CONFIG_USB_CONFIGFS_UEVENT #endif to cover the
configfs_composite_reset() function to prevent an unused function
warning when this config is unset.

Fixes: 2db4f2a2 ("FROMGIT: usb: gadget: configfs: Add a specific configFS reset callback")
Signed-off-by: J. Avila <elavila@google.com>
Change-Id: I61adc4516dc2574cc7d7a02bcc3fa7d86b8efd1d