[lldb][test] Fix GCC warnings in TestGetControlFlowKindX86.cpp

```
<...>/TestGetControlFlowKindx86.cpp:148:8: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wdangling-else]
  148 |     if (kind == eInstructionControlFlowKindReturn)
      |        ^
```

Usually llvm is a "no braces for single line body" project but
for whatever reason gcc objects to it here. Perhaps because it's
within a for loop.

Added the newlines just for readability.

Author: DavidSpickett

lldb/unittests/Disassembler/x86/TestGetControlFlowKindx86.cpp

@@ -145,14 +145,19 @@ TEST_F(TestGetControlFlowKindx86, TestX86_64Instruction) {
     EXPECT_EQ(kind, result[i]);
 
     // Also, test the DisassemblerLLVMC::MCDisasmInstance methods.
-    if (kind == eInstructionControlFlowKindReturn)
+    if (kind == eInstructionControlFlowKindReturn) {
       EXPECT_FALSE(inst_sp->IsCall());
-    if (kind == eInstructionControlFlowKindCall)
+    }
+
+    if (kind == eInstructionControlFlowKindCall) {
       EXPECT_TRUE(inst_sp->IsCall());
+    }
+
     if (kind == eInstructionControlFlowKindCall ||
         kind == eInstructionControlFlowKindJump ||
         kind == eInstructionControlFlowKindCondJump ||
-        kind == eInstructionControlFlowKindReturn)
+        kind == eInstructionControlFlowKindReturn) {
       EXPECT_TRUE(inst_sp->DoesBranch());
+    }
   }
 }