driver core: platform: fix u32 greater or equal to zero comparison

driver core: platform: fix u32 greater or equal to zero comparison

Currently the check that a u32 variable i is >= 0 is always true because
the unsigned variable will never be negative, causing the loop to run
forever.  Fix this by changing the pre-decrement check to a zero check on
i followed by a decrement of i.

Addresses-Coverity: ("Unsigned compared against 0")
Fixes: 39cc539f90d0 ("driver core: platform: Prevent resouce overflow from causing infinite loops")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/20200116175758.88396-1-colin.king@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>