Replace if_fxp's handrolled defrag function with m_defrag.
Replace if_fxp's handrolled defrag function with m_defrag.

No actual bug with the existing code, just tidying things up.

Submitted by:	hmp

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