[#2207] Removed unnecessary null check

STACK Output:
bug: anti-simplify
model: |
  %cmp17 = icmp eq %struct.node* %etype.0, null, !dbg !1268
  -->  false
stack:
  - /home/kellerb/software/root-stack/irods/iRODS/server/re/src/utils.cpp:535:0
ncore: 1
core:
  - /home/kellerb/software/root-stack/irods/iRODS/server/re/src/utils.cpp:534:0
    - null pointer dereference