KVM: x86: rename push to emulate_push for consistency

push and emulate_pop are counterparts. Rename push to emulate_push and
harmonize its function signature with emulate_pop. This should remove
a bit of cognitive load when reading this code.

Signed-off-by: Julian Stecklina <julian.stecklina@cyberus-technology.de>
Link: https://lore.kernel.org/r/20231009092054.556935-2-julian.stecklina@cyberus-technology.de


Signed-off-by: Sean Christopherson <seanjc@google.com>