bfd: Use ERR_PTR and such instead of BREADERR

No need to invent new error codes here, simply
use ERR_PTR/IS_ERR_OR_NULL and such.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Andrew Vagin <avagin@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

bfd.c

@@ -5,6 +5,7 @@
 #include <sys/mman.h>
 #include <fcntl.h>
 #include <sys/uio.h>
+#include <errno.h>
 
 #include "bug.h"
 #include "log.h"
@@ -200,7 +201,7 @@ again:
 
 	/* no full line in the buffer -- refill one */
 	if (brefill(f) < 0)
-		return BREADERR;
+		return ERR_PTR(-EIO);
 
 	refilled = true;
 

include/bfd.h

 #ifndef __CR_BFD_H__
 #define __CR_BFD_H__
+
+#include "err.h"
+
 struct bfd_buf;
 struct xbuf {
 	char *mem;		/* buffer */
@@ -23,7 +26,6 @@ static inline void bfd_setraw(struct bfd *b)
 	b->b.mem = NULL;
 }
 
-#define BREADERR	((char *)-1)
 int bfdopen(struct bfd *f);
 void bclose(struct bfd *f);
 char *breadline(struct bfd *f);

proc_parse.c

@@ -1106,19 +1106,19 @@ static int parse_timerfd(struct bfd *f, char *str, TimerfdEntry *tfy)
 		goto parse_err;
 
 	str = breadline(f);
-	if (str == NULL || str == BREADERR)
+	if (IS_ERR_OR_NULL(str))
 		goto nodata;
 	if (sscanf(str, "ticks: %llu", (unsigned long long *)&tfy->ticks) != 1)
 		goto parse_err;
 
 	str = breadline(f);
-	if (str == NULL || str == BREADERR)
+	if (IS_ERR_OR_NULL(str))
 		goto nodata;
 	if (sscanf(str, "settime flags: 0%o", &tfy->settime_flags) != 1)
 		goto parse_err;
 
 	str = breadline(f);
-	if (str == NULL || str == BREADERR)
+	if (IS_ERR_OR_NULL(str))
 		goto nodata;
 	if (sscanf(str, "it_value: (%llu, %llu)",
 		   (unsigned long long *)&tfy->vsec,
@@ -1126,7 +1126,7 @@ static int parse_timerfd(struct bfd *f, char *str, TimerfdEntry *tfy)
 		goto parse_err;
 
 	str = breadline(f);
-	if (str == NULL || str == BREADERR)
+	if (IS_ERR_OR_NULL(str))
 		goto nodata;
 	if (sscanf(str, "it_interval: (%llu, %llu)",
 		   (unsigned long long *)&tfy->isec,
@@ -1166,7 +1166,7 @@ static int parse_fdinfo_pid_s(int pid, int fd, int type,
 		str = breadline(&f);
 		if (!str)
 			break;
-		if (str == BREADERR)
+		if (IS_ERR(str))
 			goto out;
 
 		if (fdinfo_field(str, "pos") ||