chore: beautify code

Author: XuJiandong

Makefile

@@ -2,24 +2,25 @@ CC := clang
 AR := llvm-ar
 
 ifdef CFI
-$(info Info: build with CFI enabled)
-CLANG_VERSION := $(shell $(CC) --version | head -n1 | sed -n 's/.*version \([0-9]*\)\..*/\1/p')
-ifeq ($(shell test $(CLANG_VERSION) -ge 21; echo $$?),0)
-CFLAGS := --target=riscv64 -march=rv64imc_zba_zbb_zbc_zbs_zicfiss1p0_zicfilp1p0 -mabi=lp64
-CFLAGS += -menable-experimental-extensions -fcf-protection=full
-ifeq ($(CFI),unlabeled)
-CFLAGS += -mcf-branch-label-scheme=unlabeled
-else ifeq ($(CFI),func-sig)
-CFLAGS += -mcf-branch-label-scheme=func-sig
+    $(info Info: build with CFI enabled)
+    CLANG_VERSION := $(shell $(CC) --version | head -n1 | sed -n 's/.*version \([0-9]*\)\..*/\1/p')
+    ifeq ($(shell test $(CLANG_VERSION) -ge 21; echo $$?),0)
+        CFLAGS := --target=riscv64 -march=rv64imc_zba_zbb_zbc_zbs_zicfiss1p0_zicfilp1p0 -mabi=lp64
+        CFLAGS += -menable-experimental-extensions -fcf-protection=full
+        ifeq ($(CFI),unlabeled)
+            CFLAGS += -mcf-branch-label-scheme=unlabeled
+        else ifeq ($(CFI),func-sig)
+            CFLAGS += -mcf-branch-label-scheme=func-sig
+        else
+            $(error Error: CFI is set to '$(CFI)' but expected 'unlabeled' or 'func-sig')
+        endif
+    else
+        $(error Error: CFI requires clang version 21 or above, but found version $(CLANG_VERSION))
+    endif
 else
-$(error Error: CFI is set to '$(CFI)' but expected 'unlabeled' or 'func-sig')
-endif
-else
-$(error Error: CFI requires clang version 21 or above, but found version $(CLANG_VERSION))
-endif
-else
-CFLAGS := --target=riscv64 -march=rv64imc_zba_zbb_zbc_zbs -mabi=lp64
+    CFLAGS := --target=riscv64 -march=rv64imc_zba_zbb_zbc_zbs -mabi=lp64
 endif
+
 CFLAGS += -Os
 CFLAGS += -fdata-sections -ffunction-sections -fno-builtin -fvisibility=hidden -fomit-frame-pointer
 CFLAGS += -I compiler-rt/lib/builtins