Mailbox commands sent via ioctl/bsg from user applications may be
interrupted from processing by a concurrently triggered PCI function
reset. The command will not generate a completion due to the reset.  This
results in a user application hang waiting for the mailbox command to
complete.

Resolve by changing the function reset handler to detect that there was an
outstanding mailbox command and simulate a mailbox completion.  Add some
additional debug when a mailbox command times out.

Link: https://lore.kernel.org/r/20210707184351.67872-13-jsmart2021@gmail.comCo-developed-by: Justin Tee <justin.tee@broadcom.com>
Signed-off-by: Justin Tee <justin.tee@broadcom.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>