[SCSI] libfcoe: Remove mutex_trylock/restart_syscall checks

This code was incorrectly ported from fcoe.c when the
fcoe transport infrastructure was put into place. It
was originally needed in fcoe.c when dealing with
the rtnl mutex. In that code it was only needed to
avoid a lockdep false positive. In libfcoe we don't
deal with the rtnl mutex, we don't get the lockdep
false positive and therefore we don't need these
checks.

Signed-off-by: Robert Love <robert.w.love@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>