BUG: IntensityMotionCheckPanel: Fix -Wparentheses warning addressing logic issue
BUG: IntensityMotionCheckPanel: Fix -Wparentheses warning addressing logic issue

Based on the operator precedence [1], adding parenthesis around
"!qcResult.Get_result()" would be the right things to do address
the warning, that said this is incorrect since the value returned
by "Get_result()" always evaluates to 1 or 0.

[1] http://en.cppreference.com/w/c/language/operator_precedence

See https://github.com/NIRALUser/DTIPrep/issues/44

This commit improves readability introducing intermediate variables
and move the logical not operator outside the bitwise test.

This commit fixes the following warning:

```
tmp/DTIPrep/src/IntensityMotionCheckPanel.cxx: In member function ‘void IntensityMotionCheckPanel::ResultUpdate()’:
/tmp/DTIPrep/src/IntensityMotionCheckPanel.cxx:3978:33: warning: suggest parentheses around operand of ‘!’ or change ‘&’ to ‘&&’ or ‘!’ to ‘~’ [-Wparentheses]
   if( ( ( (!qcResult.Get_result()  & InterlaceWiseCheckBit) == InterlaceWiseCheckBit ) ||
                                 ^
```

NIRALUser/DTIPrep,NIRALUser/DTIPrep