xtest: regression_1000: remove unneeded stat.h include

[jonmason]

Hack to work around musl compile error:
In file included from optee-test/3.17.0-r0/recipe-sysroot/usr/include/sys/stat.h:23,
from optee-test/3.17.0-r0/git/host/xtest/regression_1000.c:25:
optee-test/3.17.0-r0/recipe-sysroot/usr/include/bits/stat.h:17:26: error: expected identifier or '(' before '[' token
17 | unsigned __unused[2];
| ^

stat.h is not needed, since it is not being used in this file. So removing it.

[jforissier]

This indicates a more fundamental problem which is that optee_os exports some header files to $(out-dir)/export-$(sm)/host_include which really belong in the TA build environment only (that is, when the C library is libutils which is the C library provided by optee_os).
In this case the conflict is caused by compiler.h which defines an __unused macro.

I believe the exports need reviewing and fixing, but in the meantime this patch looks fine to me.

Reviewed-by: Jerome Forissier <[email protected]>

[jenswi-linaro]

Acked-by: Jens Wiklander <[email protected]>

[jforissier]

@jonmason could you please add the Reviewed-by and Acked-by tags and force push? Then I will merge this. Thanks.