staging: unisys: remove LOGWRN() macros and uniklog.h

Remove the last set of macros from uniklog.h. Without LOGWRN() and
friends, uniklog.h is empty so we can delete the file itself as well.

This macro was not used a lot but the file was included in many places.

Signed-off-by: Benjamin Romer <benjamin.romer@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>