ide: avoid warning for timings calculation

gcc-7 warns about the result of a constant multiplication used as
a boolean:

drivers/ide/ide-timings.c: In function 'ide_timing_quantize':
drivers/ide/ide-timings.c:112:24: error: '*' in boolean context, suggest '&&' instead [-Werror=int-in-bool-context]
  q->setup   = EZ(t->setup   * 1000,  T);

This slightly rearranges the macro to simplify the code and avoid
the warning at the same time.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>