ps: fix for !FEATURE_PS_LONG build

Signed-off-by: Cristian Ionescu-Idbohrn <cii@axis.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/procps/ps.c b/procps/ps.c
index 3815c1e..4727b21 100644
--- a/procps/ps.c
+++ b/procps/ps.c
@@ -693,8 +693,10 @@
  * We also show STIME (standard says that -f shows it, -l doesn't).
  */
 		puts("S   UID   PID  PPID   VSZ   RSS TTY   STIME TIME     CMD");
+#if ENABLE_FEATURE_PS_LONG
 		now = time(NULL);
 		sysinfo(&info);
+#endif
 	}
 	else {
 		puts("  PID USER       VSZ STAT COMMAND");