fix unit test warnings (#246)

* fix conversion warnings

* fix differs in parameter lists warnings
diff --git a/tests/test_openclhpp.cpp b/tests/test_openclhpp.cpp
index cb112b5..72a5a8e 100644
--- a/tests/test_openclhpp.cpp
+++ b/tests/test_openclhpp.cpp
@@ -1789,7 +1789,7 @@
     kernelPool[0].setArg(2, cl::Local(123));
 }
 
-void testKernelSetArgBySetKernelArgSVMPointerWithUniquePtrType()
+void testKernelSetArgBySetKernelArgSVMPointerWithUniquePtrType(void)
 {
 #if CL_HPP_TARGET_OPENCL_VERSION >= 200
     std::unique_ptr<int> buffer(new int(1000));
@@ -1798,7 +1798,7 @@
 #endif
 }
 
-void testKernelSetArgBySetKernelArgSVMPointerWithVectorType()
+void testKernelSetArgBySetKernelArgSVMPointerWithVectorType(void)
 {
 #if CL_HPP_TARGET_OPENCL_VERSION >= 200
     VECTOR_CLASS<int> vec(1000);
@@ -1807,7 +1807,7 @@
 #endif
 }
 
-void testKernelSetArgBySetKernelArgSVMPointerWithPointerType()
+void testKernelSetArgBySetKernelArgSVMPointerWithPointerType(void)
 {
 #if CL_HPP_TARGET_OPENCL_VERSION >= 200
     cl_mem *memory = &bufferPool[1]();
@@ -1854,12 +1854,12 @@
     return CL_SUCCESS;
 }
 
-void testKernelSetSVMPointers()
+void testKernelSetSVMPointers(void)
 {
 #if CL_HPP_TARGET_OPENCL_VERSION >= 200
     clSetKernelExecInfo_StubWithCallback(clSetKernelExecInfo_setSVMPointers);
   
-    cl::vector<void *> vec = { (void *)0xaabbccdd, (void *)0xddccbbaa };
+    cl::vector<void *> vec = { (void *)(size_t)0xaabbccdd, (void *)(size_t)0xddccbbaa };
     cl_int ret = kernelPool[0].setSVMPointers(vec);
 
     cl_int expected = CL_SUCCESS;
@@ -1880,7 +1880,7 @@
 
     return CL_SUCCESS;
 }
-void testKernelEnableFineGrainedSystemSVM()
+void testKernelEnableFineGrainedSystemSVM(void)
 {
 #if CL_HPP_TARGET_OPENCL_VERSION >= 200
     clSetKernelExecInfo_StubWithCallback(clSetKernelExecInfo_EnableFineGrainedSystemSVM);
@@ -3622,7 +3622,7 @@
     }
     return CL_SUCCESS;
 }
-void testDevice_GetInfo_CLDeviceVendorID()
+void testDevice_GetInfo_CLDeviceVendorID(void)
 {
     cl_uint expected = 0xABCD;
     clGetDeviceInfo_StubWithCallback(
@@ -3647,7 +3647,7 @@
     }
     return CL_SUCCESS;
 }
-void testDevice_GetInfo_CLDeviceImageSupport()
+void testDevice_GetInfo_CLDeviceImageSupport(void)
 {
     cl_bool expected = true;
     clGetDeviceInfo_StubWithCallback(
@@ -3675,7 +3675,7 @@
     }
     return CL_SUCCESS;
 }
-void testDevice_GetInfo_CLDeviceName()
+void testDevice_GetInfo_CLDeviceName(void)
 {
     cl::string expected = "testDeviceName";
     clGetDeviceInfo_StubWithCallback(clGetInfo_testDeviceGetInfoCLDeviceName);
@@ -4164,7 +4164,7 @@
     return CL_INVALID_OPERATION;
 }
 
-void testTemplateGetSemaphoreHandleForTypeKHR()
+void testTemplateGetSemaphoreHandleForTypeKHR(void)
 {
     clGetDeviceInfo_StubWithCallback(clGetDeviceInfo_platform);
     clGetPlatformInfo_StubWithCallback(clGetPlatformInfo_version_2_0);
@@ -4346,7 +4346,7 @@
     TEST_ASSERT_EQUAL_PTR(svm_pointer, testMemory);
     delete[] (int*) svm_pointer; 
 }
-void testSVMMemoryAllocation()
+void testSVMMemoryAllocation(void)
 {
 #if CL_HPP_TARGET_OPENCL_VERSION >= 200
     cl::SVMAllocator<int, cl::SVMTraitCoarse<>> svmAllocator;
@@ -4427,7 +4427,7 @@
     return CL_INVALID_OPERATION;
 }
 
-void testTemplateGetImageRequirementsInfo()
+void testTemplateGetImageRequirementsInfo(void)
 {
     cl::Context context(make_context(0));
     cl_device_id device_expect = make_device_id(0);