arm64: Remove the __user annotation for the restore_za_context() argument

The struct user_ctx *user pointer passed to restore_za_context() is not
a user point but a structure containing several __user pointers. Remove
the __user annotation.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Fixes: 39782210 ("arm64/sme: Implement ZA signal handling")
Reported-by: kernel test robot <lkp@intel.com>
Cc: Mark Brown <broonie@kernel.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220601171338.2143625-1-catalin.marinas@arm.com


Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>