libutils: fix signed/unsigned comparison warnings

Change-Id: Ib283c85a404a20688c5357fa513e5d07c2f42803
diff --git a/libutils/tests/BitSet_test.cpp b/libutils/tests/BitSet_test.cpp
index 38b668a..59d913e 100644
--- a/libutils/tests/BitSet_test.cpp
+++ b/libutils/tests/BitSet_test.cpp
@@ -138,11 +138,11 @@
 TEST_F(BitSet32Test, GetIndexOfBit) {
     b1.markBit(1);
     b1.markBit(4);
-    EXPECT_EQ(b1.getIndexOfBit(1), 0);
-    EXPECT_EQ(b1.getIndexOfBit(4), 1);
+    EXPECT_EQ(0U, b1.getIndexOfBit(1));
+    EXPECT_EQ(1U, b1.getIndexOfBit(4));
     b1.markFirstUnmarkedBit();
-    EXPECT_EQ(b1.getIndexOfBit(1), 1);
-    EXPECT_EQ(b1.getIndexOfBit(4), 2);
+    EXPECT_EQ(1U, b1.getIndexOfBit(1));
+    EXPECT_EQ(2U, b1.getIndexOfBit(4));
 }
 
 class BitSet64Test : public testing::Test {
@@ -260,11 +260,11 @@
 TEST_F(BitSet64Test, GetIndexOfBit) {
     b1.markBit(10);
     b1.markBit(40);
-    EXPECT_EQ(b1.getIndexOfBit(10), 0);
-    EXPECT_EQ(b1.getIndexOfBit(40), 1);
+    EXPECT_EQ(0U, b1.getIndexOfBit(10));
+    EXPECT_EQ(1U, b1.getIndexOfBit(40));
     b1.markFirstUnmarkedBit();
-    EXPECT_EQ(b1.getIndexOfBit(10), 1);
-    EXPECT_EQ(b1.getIndexOfBit(40), 2);
+    EXPECT_EQ(1U, b1.getIndexOfBit(10));
+    EXPECT_EQ(2U, b1.getIndexOfBit(40));
 }
 
 } // namespace android