lib: add safe_gethostname()

Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Reviewed-by: Cyril Hrubis <chrubis@suse.cz>
diff --git a/lib/safe_net.c b/lib/safe_net.c
index 98a79cf..cae77b5 100644
--- a/lib/safe_net.c
+++ b/lib/safe_net.c
@@ -183,3 +183,17 @@
 
 	return rval;
 }
+
+int safe_gethostname(const char *file, const int lineno,
+		     char *name, size_t size)
+{
+	int rval = gethostname(name, size);
+
+	if (rval < 0) {
+		tst_brkm(TBROK | TERRNO, NULL,
+			 "%s:%d: gethostname(%p, %zu) failed",
+			 file, lineno, name, size);
+	}
+
+	return rval;
+}