USB: cypress_m8: remove invalid Clear-Halt

This patch (as1265) removes an erroneous call to usb_clear_halt from
the cypress_m8 driver.  The call isn't valid because it is made from
interrupt context whereas usb_clear_halt is a blocking routine.

Presumably the code has never been executed; if it did it would cause
an oops.  So instead treat -EPIPE like any other sort of unexplained
error.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>