usb: musb: fix compile warning

When running 100 randconfig iterations, I found
the following warning:

drivers/usb/musb/musb_core.c: In function ‘musb_init_controller’:
drivers/usb/musb/musb_core.c:1981:1: warning: label ‘fail5’ defined \
	but not used [-Wunused-label]

this patch fixes it by removing the unnecessary
ifdef CONFIG_SYSFS.

Signed-off-by: Felipe Balbi <balbi@ti.com>