Let XML generator append a trailing newline

By appending a newline to the generated XML data, we prevent the output
from messing with the command prompt when using 'cat' on a shell.
Futhermore, when using line-buffered output, the trailing newline
ensures that the output gets gets properly flushed.

repos/os/include/util/xml_generator.h

@@ -232,7 +232,10 @@ class Genode::Xml_generator
 		:
 			_out_buffer(dst, dst_len)
 		{
-			if (dst) node(name, func);
+			if (dst) {
+				node(name, func);
+				_out_buffer.append('\n');
+			}
 		}
 
 		template <typename FUNC>

repos/os/run/xml_generator.run

@@ -45,7 +45,7 @@ compare_output_to {
 	[init -> test-xml_generator] 	</label>
 	[init -> test-xml_generator] </config>
 	[init -> test-xml_generator] 
-	[init -> test-xml_generator] used 199 bytes
+	[init -> test-xml_generator] used 200 bytes
 	[init -> test-xml_generator] buffer exceeded (expected error)
 	[init -> test-xml_generator] --- XML generator test finished ---
 }

repos/os/src/test/xml_generator/main.cc

@@ -58,7 +58,7 @@ int main(int argc, char **argv)
 	 * corresponding run script).
 	 */
 	size_t used = fill_buffer_with_xml(dst, sizeof(dst));
-	printf("result:\n\n%s\n\nused %zd bytes\n", dst, used);
+	printf("result:\n\n%s\nused %zd bytes\n", dst, used);
 
 	/*
 	 * Test buffer overflow