There is not a consistent pattern for checking Hyper-V hypercall status.
Existing code uses a number of variants.  The variants work, but a consistent
pattern would improve the readability of the code, and be more conformant
to what the Hyper-V TLFS says about hypercall status.

Implemented new helper functions hv_result(), hv_result_success(), and
hv_repcomp().  Changed the places where hv_do_hypercall() and related variants
are used to use the helper functions.
Signed-off-by: Joseph Salisbury <joseph.salisbury@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1618620183-9967-2-git-send-email-joseph.salisbury@linux.microsoft.comSigned-off-by: Wei Liu <wei.liu@kernel.org>