usb: core: fix quirks_param_set() writing to a const pointer

[ Upstream commit b1b6bed3b5036509b449b5965285d5057ba42527 ]

The function quirks_param_set() takes as argument a const char* pointer
to the new value of the usbcore.quirks parameter. It then casts this
pointer to a non-const char* pointer and passes it to the strsep()
function, which overwrites the value.

Fix this by creating a copy of the value using kstrdup() and letting
that copy be written to by strsep().

Fixes: 027bd6ca ("usb: core: Add "quirks" parameter for usbcore")
Signed-off-by: Kars Mulder <kerneldev@karsmulder.nl>

Link: https://lore.kernel.org/r/5ee2-5f048a00-21-618c5c00@230659773


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>