usb: chipidea: drop redundant NULL check
usb: chipidea: drop redundant NULL check

Currently, gadget can't be NULL in _gadget_stop_activity().

Signed-off-by: Alexander Shishkin <0125b3d2989cefbb754a245b989e89659aa67db8@linux.intel.com>
Reported-by: Michael Grzeschik <56a917ffddddef251f53499c2bdc20635fcae7f7@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <4645f7897fd33786a2ee1264d590b3c400559d85@linuxfoundation.org>

TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs