Fix FSM coverage hierarchy being emitted as an absolute path (#8421)

AstNodeCoverDecl::hier() is relative to the scope the declaration is
emitted from, as V3EmitCImp builds the reported path as 'vlNamep + hierp',
and that is how V3Coverage uses it. V3FsmDetect instead set it to the
absolute scope name, so the instance path was counted twice.

This was masked whenever the owning module was inlined, as the declaration
then ended up in the top scope. With inlining disabled, an FSM in an
instance reported 'top.t.forced_wide_u.t.forced_wide_u'. In the inlined
case it reported 'top.TOP', leaking the internal top wrapper name into
user visible coverage output, rather than plain 'top'.

src/V3FsmDetect.cpp

@@ -2194,7 +2194,6 @@ class FsmLowerVisitor final {
                                         graph.stateVarName(),
                                         "",
                                         statep->label()};
-            declp->hier(scopep->prettyName());
             modp->addStmtsp(declp);
             AstNodeExpr* const guardp
                 = andExpr(flp,
@@ -2231,7 +2230,6 @@ class FsmLowerVisitor final {
                                             fromVertexp->label(),
                                             toStatep->label(),
                                             fsmTag};
-                declp->hier(scopep->prettyName());
                 modp->addStmtsp(declp);
                 AstNodeExpr* guardp = nullptr;
                 if (fromVertexp->isResetAny()) {