Revert "arch/arm/boot64: Check fit_decompress() return value"

This reverts commit d82ea582354c8344f492c1b39f167119ffe79c96.

Reason for revert: ToT broken tested on Quenbi/Quartz.

```
TPM: secdata_firmware unchanged
nvdata unchanged
tpm_get_response: command 0x121, return code 0x0
TPM: secdata_kernel locked
Shutting down all USB controllers.
Exiting depthcharge with code 4 at timestamp: 15592912
LZ4 decompressing kernel@1 to 0xdf7ff058
ERROR: Failed to decompress kernel
```


BUG=b:482448971
TEST=Able to build and boot google/quartz.

Original change's description:
> arch/arm/boot64: Check fit_decompress() return value
>
> When the kernel format is incorrect, decompression functions such as
> ulz4ln() usually silently return 0 directly due to magic mismatch.
> Currently the return value of the first fit_decompress() call for
> scratch buffer isn't checked. Therefore, when the kernel format is
> wrong, we will see a misleading error message:
>
>  ERROR: Invalid kernel magic: 0xf1204be8 != 0x644d5241
>
> Add a return value check and print a more accurate error message on
> decompression failure.
>
> Also initialize the scratch to zero, and fix the extra newline in an
> error log.
>
> BUG=none
> TEST=emerge-rauru depthcharge
> BRANCH=none
>
> Change-Id: Ie89ebaa282a85f94d4b88a09e49ab0f94ba9a4f5
> Signed-off-by: Yu-Ping Wu <yupingso@chromium.org>
> Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/depthcharge/+/7544822
> Reviewed-by: Yidi Lin <yidilin@google.com>
> Commit-Queue: Yidi Lin <yidilin@google.com>

BUG=none

Change-Id: Ia558849a751c27cd45a247ea15a71022cefea6dc
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/depthcharge/+/7553670
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Auto-Submit: Subrata Banik <subratabanik@chromium.org>
Commit-Queue: Subrata Banik <subratabanik@chromium.org>
Commit-Queue: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Tested-by: Subrata Banik <subratabanik@chromium.org>
Reviewed-by: Jayvik Desai <jayvik@google.com>