check: Don't forget to init mountns

Otherwise fstatat fails as

> > $ ./crtools check
> > Error (sk-unix.c: 283): Can't stat socket 12547 (./var/run/sdp): Bad file descriptor
Reported-by: "Muralidhar, Rajeev D" <rajeev.d.muralidhar@intel.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
CC: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

cr-check.c

@@ -16,6 +16,7 @@
 #include "files.h"
 #include "sk-inet.h"
 #include "proc_parse.h"
+#include "mount.h"
 
 static int check_map_files(void)
 {
@@ -334,6 +335,11 @@ int cr_check(void)
 {
 	int ret = 0;
 
+	if (mntns_collect_root(getpid())) {
+		pr_err("Can't collect root mount point\n");
+		return -1;
+	}
+
 	ret |= check_map_files();
 	ret |= check_sock_diag();
 	ret |= check_ns_last_pid();