[ Upstream commit 7ef539c8 ]

Fixing the IO stats update (Active IOs and IO completion) to prevent
"Number of Active IOs" from becoming negative in the fnistats output.
Signed-off-by: Satish Kharat <satishkh@cisco.com>
Signed-off-by: Sesidhar Baddela <sebaddel@cisco.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>