Check that periph is non-NULL before dereferencing it.
Check that periph is non-NULL before dereferencing it.

Reported by:	"Ted Unangst" <tedu@coverity.com>
Approved by:	rwatson (mentor), ken (scsi@)

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase