KVM: SVM: Load %gs earlier if CONFIG_X86_32_LAZY_GS=n

With CONFIG_CC_STACKPROTECTOR, we need a valid %gs at all times, so disable
lazy reload and do an eager reload immediately after the vmexit.

Reported-by: IVAN ANGELOV <ivangotoy@gmail.com>
Acked-By: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>