Fix coding style issue

Fix coding style issue

Replace:

  if (-1 == foo())

with:

  if (foo() == -1)

While this coding style is not in direct contravention of our currently
ratified CODING_STYLE treaty, it could be argued that the Article 3 of
the European Convention on Human Rights (prohibiting torture and "inhuman
or degrading treatment") reads on the matter.

[This commit message was brought to you without humour, as is evidenced
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Signed-off-by: Mark McLoughlin <[email protected]>
Cc: Avi Kivity <[email protected]>
Cc: Gerd Hoffmann <[email protected]>
Signed-off-by: Blue Swirl <[email protected]>