qlit: rename compare_litqobj_to_qobj() to qlit_equal_qobject()

qlit: rename compare_litqobj_to_qobj() to qlit_equal_qobject()

compare_litqobj_to_qobj() lacks a qlit_ prefix.  Moreover, "compare"
suggests -1, 0, +1 for less than, equal and greater than.  The
function actually returns non-zero for equal, zero for unequal.
Rename to qlit_equal_qobject().

Its return type will be cleaned up in the next patch.

Signed-off-by: Marc-André Lureau <[email protected]>
Reviewed-by: Markus Armbruster <[email protected]>
Message-Id: <20170825105913[email protected]>
Signed-off-by: Markus Armbruster <[email protected]>