x86: altp2m cleanup work

x86: altp2m cleanup work

Indent goto labels by one space.
Inline (header) altp2m functions.
In do_altp2m_op(), during the sanity check of the passed command,
return -EOPNOTSUPP if not a valid command.
In do_altp2m_op(), when evaluating a command, ASSERT_UNREACHABLE()
if the command is not recognizable.  The sanity check above should
have triggered the return of -EOPNOTSUPP.
Make hvm_funcs.altp2m_supported "bool" instead of "bool_t".
Make hvm_altp2m_supported() and altp2m_vcpu_emulate_ve() return
bool (rather than return void()).

Signed-off-by: Paul Lai <paul.c.lai@intel.com>
Acked-by: Jan Beulich <jbeulich@suse.com>