target/i386: the sgx_epc_get_section stub is reachable

The sgx_epc_get_section stub is reachable from cpu_x86_cpuid.  It
should not assert, instead it should just return true just like
the "real" sgx_epc_get_section does when SGX is disabled.

Reported-by: Vladimír Beneš <vbenes@redhat.com>
Cc: qemu-stable@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20220201190941.106001-1-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit 219615740425d9683588207b40a365e6741691a6)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

hw/i386/sgx-stub.c

@@ -34,5 +34,5 @@ void pc_machine_init_sgx_epc(PCMachineState *pcms)
 
 bool sgx_epc_get_section(int section_nr, uint64_t *addr, uint64_t *size)
 {
-    g_assert_not_reached();
+    return true;
 }