headers: Drop SCM_MAX_FD internal variable

This limit is not exported by a kernel, so no need
to "explicitly" define it pretending that it's immutable.

Still I kept this name in comment just to give reader
a tip where CR_SCM_MAX_FD came from.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

arch/arm/include/asm/types.h

@@ -152,11 +152,6 @@ enum kcmp_type {
 	KCMP_TYPES,
 };
 
-/* For UNIX sockets data */
-#ifndef SCM_MAX_FD
-# define SCM_MAX_FD	253
-#endif
-
 /* File handle */
 typedef struct {
 	u32 bytes;

arch/x86/include/asm/types.h

@@ -176,11 +176,6 @@ enum kcmp_type {
 	KCMP_TYPES,
 };
 
-/* For UNIX sockets data */
-#ifndef SCM_MAX_FD
-# define SCM_MAX_FD	253
-#endif
-
 /* File handle */
 typedef struct {
 	u32 bytes;

include/util-pie.h

@@ -15,7 +15,7 @@
 
 /*
  * Because of kernel doing kmalloc for user data passed
- * in SCM messages, and there is SCM_MAX_FD as a limit
+ * in SCM messages, and there is kernel's SCM_MAX_FD as a limit
  * for descriptors passed at once we're trying to reduce
  * the pressue on kernel memory manager and use predefined
  * known to work well size of the message buffer.

pie/util-fd.c

@@ -33,7 +33,6 @@ static int *scm_fdset_init(struct scm_fdset *fdset, struct sockaddr_un *saddr,
 {
 	struct cmsghdr *cmsg;
 
-	BUILD_BUG_ON(CR_SCM_MAX_FD > SCM_MAX_FD);
 	BUILD_BUG_ON(sizeof(fdset->msg_buf) < (CMSG_SPACE(sizeof(int) * CR_SCM_MAX_FD)));
 
 	fdset->iov.iov_base		= fdset->opts;