8322815: Eliminate -Wparentheses warnings in shenandoah code

Reviewed-by: shade, zgu

Author: Kim Barrett

src/hotspot/share/gc/shenandoah/c2/shenandoahSupport.cpp

@@ -2158,7 +2158,7 @@ void MemoryGraphFixer::collect_memory_nodes() {
           assert(m != nullptr || (c->is_Loop() && j == LoopNode::LoopBackControl && iteration == 1) || _phase->C->has_irreducible_loop() || has_never_branch(_phase->C->root()), "expect memory state");
           if (m != nullptr) {
             if (m == prev_region && ((c->is_Loop() && j == LoopNode::LoopBackControl) || (prev_region->is_Phi() && prev_region->in(0) == c))) {
-              assert(c->is_Loop() && j == LoopNode::LoopBackControl || _phase->C->has_irreducible_loop() || has_never_branch(_phase->C->root()), "");
+              assert((c->is_Loop() && j == LoopNode::LoopBackControl) || _phase->C->has_irreducible_loop() || has_never_branch(_phase->C->root()), "");
               // continue
             } else if (unique == nullptr) {
               unique = m;