Fix an error in float not equal operation

[gergocs]

Signed-off-by: Gergo Csizi gergocs@inf.u-szeged.hu

[zherczeg]

Please add some tests

[gergocs]

Patch is ready for review

[zherczeg]

How do you detected this issue? Normally, a not equal should fail if either is nan, but it will return with true here. In other words !(a == b) is not the same as (a != b) for float numbers.

[gergocs]

The reference manual says the not equal operation should be unordered or not equal.