Use (D)CHECK_ALIGNED more.

Change-Id: I9d740f6a88d01e028d4ddc3e4e62b0a73ea050af
diff --git a/compiler/utils/arm/assembler_arm.cc b/compiler/utils/arm/assembler_arm.cc
index 09d2270..0e3e08c 100644
--- a/compiler/utils/arm/assembler_arm.cc
+++ b/compiler/utils/arm/assembler_arm.cc
@@ -252,11 +252,11 @@
   if (offset_ < 0) {
     int32_t off = -offset_;
     CHECK_LT(off, 1024);
-    CHECK_EQ((off & 3 /* 0b11 */), 0);    // Must be multiple of 4.
+    CHECK_ALIGNED(off, 4);
     encoding = (am ^ (1 << kUShift)) | off >> 2;  // Flip U to adjust sign.
   } else {
     CHECK_LT(offset_, 1024);
-    CHECK_EQ((offset_ & 3 /* 0b11 */), 0);    // Must be multiple of 4.
+    CHECK_ALIGNED(offset_, 4);
     encoding =  am | offset_ >> 2;
   }
   encoding |= static_cast<uint32_t>(rn_) << 16;