Comparison, does not equal zero, is redundant

'if (foo != 0)'  is equal to  'if (foo)'

Typical kernel coding style is to use the shorter form.

Remove unnecessary non-zero comparison.
Signed-off-by: Tobin C. Harding <me@tobin.cc>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>