Fix Pre-allgather Layernorm bad PCC when use 1D reduction

[yugaoTT]

Ticket

Link to Github Issue

Problem description

Currently due to the usage of 2D reduction, the 1d reduction is not tested for Pre-allgather Layernorm, after disable the 2d, it has pcc error.

What's changed

problem is output cb is wrong, changed to correct output cb.

Checklist

• Post commit CI passes
• Blackhole Post commit (if applicable)
• Model regression CI testing passes (if applicable)
• Device performance regression CI testing passes (if applicable)
• (For models and ops writers) Full new models tests passes
• New/Existing tests provide coverage for changes