[BOLT][AArch64] Fix adr-relaxation.s test (#143151)
On some AArch64 machines the splitting was inconsistent.
This causes cold `foo` to have a `mov` instruction before adrp.
```
<foo.cold.0>:
mov x0, #0x0 // =0
adrp x1, 0x600000 <_start>
add x1, x1, #0x14
ret
```
This patch removes the `mov` instruction right above .L2, making
splitting deterministic.
