staging: rtl8188eu: clean up comparsion style issues

staging: rtl8188eu: clean up comparsion style issues

Move constants to the right side of comparsions to follow kernel
coding style and clear checkpatch warnings. In case of comparsion
to _FAIL we can use '!' since _FAIL is defined as '0'.

WARNING: Comparisons should place the constant on the right side of the test

Signed-off-by: Michael Straube <straube.linux@gmail.com>
Link: https://lore.kernel.org/r/20200917071330.31740-2-straube.linux@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>