vsh: Don't check for OOM in vshGetTypedParamValue()

vsh: Don't check for OOM in vshGetTypedParamValue()

Both function description and function itself mention check for
OOM which can't happen really. There was a bug in glib where
g_strdup_*() might have not aborted on OOM, but we have our own
implementation when dealing with broken glib (see
vir_g_strdup_printf()). Therefore, checking for OOM is redundant
and can never be true.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>