selftests/sgx: Fix uninitialized pointer dereference in error path

selftests/sgx: Fix uninitialized pointer dereference in error path

[ Upstream commit 79eba8c924f7decfa71ddf187d38cb9f5f2cd7b3 ]

Ensure ctx is zero-initialized, such that the encl_measure function will
not call EVP_MD_CTX_destroy with an uninitialized ctx pointer in case of an
early error during key generation.

Fixes: 2adcba79e69d ("selftests/x86: Add a selftest for SGX")
Signed-off-by: Jo Van Bulck <jo.vanbulck@cs.kuleuven.be>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Acked-by: Kai Huang <kai.huang@intel.com>
Link: https://lore.kernel.org/all/20231005153854.25566-2-jo.vanbulck%40cs.kuleuven.be
Signed-off-by: Sasha Levin <sashal@kernel.org>