pgsql: If we're gonna use ExecRelationIsTargetRelation here, might as

Log Message:
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If we're gonna use ExecRelationIsTargetRelation here, might as well
simplify a bit further.

Modified Files:
--------------
pgsql/src/backend/executor:
execUtils.c (r1.148 -> r1.149)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/executor/execUtils.c.diff?r1=1.148&r2=1.149)