pie/piegen: add space at pr_perror()

As no user does it explicitly, do this in define, it shall look nicer
than:
parasite_blob: Error (pie/piegen/main.c:121): Can't open file file.oNo such file or directory
Signed-off-by: Dmitry Safonov <dsafonov@virtuozzo.com>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>

criu/pie/piegen/piegen.h

@@ -30,6 +30,6 @@ extern int handle_elf_ppc64(void *mem, size_t size);
 #define pr_debug(fmt, ...)	printf("%s: "fmt, opts.stream_name, ##__VA_ARGS__)
 
 #define pr_err(fmt, ...)	fprintf(stderr, "%s: Error (%s:%d): "fmt, opts.stream_name, __FILE__, __LINE__, ##__VA_ARGS__)
-#define pr_perror(fmt, ...)	fprintf(stderr, "%s: Error (%s:%d): "fmt "%m\n", opts.stream_name, __FILE__, __LINE__, ##__VA_ARGS__)
+#define pr_perror(fmt, ...)	fprintf(stderr, "%s: Error (%s:%d): "fmt ": %m\n", opts.stream_name, __FILE__, __LINE__, ##__VA_ARGS__)
 
 #endif /* __ELFTIL_H__ */