x86emul: centralize put_fpu() invocations

x86emul: centralize put_fpu() invocations

..., splitting parts of it into check_*() macros. This is in
preparation of making ->put_fpu() do further adjustments to register
state. (Some of the check_xmm() invocations could be avoided, as in
some of the cases no insns handled there can actually raise #XM, but I
think we're better off keeping them to avoid later additions of further
insn patterns rendering the lack of the check a bug.)

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>