Simplify return in __memcmp16

Test: build
Change-Id: I9b67c39c66ae7b4ebb07e5d23b0cfa00207a04ac
diff --git a/runtime/arch/arm/memcmp16_arm.S b/runtime/arch/arm/memcmp16_arm.S
index b623a2a..0195b05 100644
--- a/runtime/arch/arm/memcmp16_arm.S
+++ b/runtime/arch/arm/memcmp16_arm.S
@@ -150,11 +150,7 @@
         bne         8f
         /* restore registers and return */
         mov         r0, #0
-        pop         {r4, lr}
-        .cfi_restore r4
-        .cfi_restore lr
-        .cfi_adjust_cfa_offset -8
-        bx          lr
+        pop         {r4, pc}
 
 2:      /* the last 2 words are different, restart them */
         ldrh        r0, [r3, #-4]
@@ -164,11 +160,7 @@
         ldrheq      ip, [r1, #-2]
         subseq      r0, r0, ip
         /* restore registers and return */
-        pop         {r4, lr}
-        .cfi_restore r4
-        .cfi_restore lr
-        .cfi_adjust_cfa_offset -8
-        bx          lr
+        pop         {r4, pc}
 
         /* process the last few words */
 8:      ldrh        r0, [r3], #2
@@ -179,12 +171,7 @@
         bne         8b
 
 9:      /* restore registers and return */
-        pop         {r4, lr}
-        .cfi_restore r4
-        .cfi_restore lr
-        .cfi_adjust_cfa_offset -8
-        bx          lr
-
+        pop         {r4, pc}
 
 5:      /*************** non-congruent case ***************/