usb: usb_create_context(): Fix usb_{reset,open}_pipe{s,}() error paths
usb: usb_create_context(): Fix usb_{reset,open}_pipe{s,}() error paths

Properly cleanup the context when either usb_reset_pipes() or
usb_open_pipe() fails in usb_create_context().

This will also ensure that errno is set properly in these cases.

Signed-off-by: Lars-Peter Clausen <3318dc5ce3e4fb7c28a0b841b6801c884e1d0896@metafoo.de>

analogdevicesinc/libiio,analogdevicesinc/libiio,analogdevicesinc/libiio,analogdevicesinc/libiio