build: fix compiler warnings (GCC 5.3.1)

modules/core/test/test_math.cpp

@@ -2384,7 +2384,7 @@ TEST(Core_SolvePoly, regression_5599)
         double prec;
         prec = cv::solvePoly(coefs, r);
         EXPECT_LE(prec, 1e-6);
-        EXPECT_EQ(4, r.total());
+        EXPECT_EQ(4u, r.total());
         //std::cout << "Preciseness = " << prec << std::endl;
         //std::cout << "roots:\n" << r << "\n" << std::endl;
         ASSERT_EQ(CV_32FC2, r.type());
@@ -2400,7 +2400,7 @@ TEST(Core_SolvePoly, regression_5599)
         double prec;
         prec = cv::solvePoly(coefs, r);
         EXPECT_LE(prec, 1e-6);
-        EXPECT_EQ(2, r.total());
+        EXPECT_EQ(2u, r.total());
         //std::cout << "Preciseness = " << prec << std::endl;
         //std::cout << "roots:\n" << r << "\n" << std::endl;
         ASSERT_EQ(CV_32FC2, r.type());

modules/core/test/test_utils.cpp

@@ -223,13 +223,13 @@ TEST(CommandLineParser, positional_regression_5074_equal_sign)
 TEST(AutoBuffer, allocate_test)
 {
     AutoBuffer<int, 5> abuf(2);
-    EXPECT_EQ(2, abuf.size());
+    EXPECT_EQ(2u, abuf.size());
 
     abuf.allocate(4);
-    EXPECT_EQ(4, abuf.size());
+    EXPECT_EQ(4u, abuf.size());
 
     abuf.allocate(6);
-    EXPECT_EQ(6, abuf.size());
+    EXPECT_EQ(6u, abuf.size());
 }
 
 } // namespace