Delete braces for complying with conding standard

It resolves
#147262 (comment)

Author: oojahooo

mlir/lib/Dialect/SPIRV/IR/TargetAndABI.cpp

@@ -185,12 +185,10 @@ spirv::TargetEnvAttr spirv::lookupTargetEnv(Operation *op) {
       break;
 
     if (auto arrAttr = op->getAttrOfType<ArrayAttr>("targets")) {
-      for (auto attr : arrAttr) {
+      for (auto attr : arrAttr)
         if (auto spirvTargetEnvAttr =
-                llvm::dyn_cast<spirv::TargetEnvAttr>(attr)) {
+                llvm::dyn_cast<spirv::TargetEnvAttr>(attr))
           return spirvTargetEnvAttr;
-        }
-      }
     }
 
     if (auto attr = op->getAttrOfType<spirv::TargetEnvAttr>(