Fix `tautological-compare` warnings
The build logs with clang show several tautological-compare
warnings which look like really buggy code, for example:
/builds/staging/dune-uggrid/gm/algebra.cc:5233:58: warning: self-comparison always evaluates to true [-Wtautological-compare]
if (((putSkipFirst) && (VECSKIP(theVector) & skipPat == skipPat)) ||
^
/builds/staging/dune-uggrid/gm/algebra.cc:5233:48: warning: & has lower precedence than ==; == will be evaluated first [-Wparentheses]
if (((putSkipFirst) && (VECSKIP(theVector) & skipPat == skipPat)) ||
^~~~~~~~~~~~~~~~~~~~
/builds/staging/dune-uggrid/gm/algebra.cc:5233:48: note: place parentheses around the '==' expression to silence this warning
if (((putSkipFirst) && (VECSKIP(theVector) & skipPat == skipPat)) ||
^
( )
/builds/staging/dune-uggrid/gm/algebra.cc:5233:48: note: place parentheses around the & expression to evaluate it first
if (((putSkipFirst) && (VECSKIP(theVector) & skipPat == skipPat)) ||
~~~~~~~~~~~~~~~~~~~^~~~~~~~~
Here a & mask == mask
will be evaluated as a & (mask == mask)
instead of the intended (a & mask) == mask
.