Make test suites compatible with #include <assert.h>

Don't use the macro name assert. It's technically permitted as long as
<assert.h> is not included, but it's fragile, because it means the
code and any header that it includes must not include <assert.h>.
diff --git a/tests/suites/target_test.function b/tests/suites/target_test.function
index 56abf29..e4c3e30 100644
--- a/tests/suites/target_test.function
+++ b/tests/suites/target_test.function
@@ -13,11 +13,11 @@
  */
 #define INCR_ASSERT(p, start, len, step) do                     \
 {                                                               \
-    assert( ( p ) >= ( start ) );                               \
-    assert( sizeof( *( p ) ) == sizeof( *( start ) ) );         \
+    TEST_HELPER_ASSERT( ( p ) >= ( start ) );                               \
+    TEST_HELPER_ASSERT( sizeof( *( p ) ) == sizeof( *( start ) ) );         \
     /* <= is checked to support use inside a loop where         \
        pointer is incremented after reading data.       */      \
-    assert( (uint32_t)( ( ( p ) - ( start ) ) + ( step ) ) <= ( len ) );\
+    TEST_HELPER_ASSERT( (uint32_t)( ( ( p ) - ( start ) ) + ( step ) ) <= ( len ) );\
     ( p ) += ( step );                                          \
 }                                                               \
 while( 0 )
@@ -127,7 +127,7 @@
     /* Read data length */
     *data_len = receive_uint32();
     data = (uint8_t *)malloc( *data_len );
-    assert( data != NULL );
+    TEST_HELPER_ASSERT( data != NULL );
 
     greentea_getc(); // read ';' received after key i.e. *data_len
 
@@ -221,7 +221,7 @@
     hex_count = find_hex_count(count, data, data_len);
 
     params = (void **)malloc( sizeof( void *) * ( count + hex_count ) );
-    assert( params != NULL );
+    TEST_HELPER_ASSERT( params != NULL );
     cur = params;
 
     p = data;
@@ -360,7 +360,7 @@
         {
             /* Read dependency count */
             count = *p;
-            assert( count < data_len );
+            TEST_HELPER_ASSERT( count < data_len );
             INCR_ASSERT( p, data, data_len, sizeof( uint8_t ) );
             ret = verify_dependencies( count, p );
             if ( ret != DEPENDENCY_SUPPORTED )