[RFC PATCH] __fxstat: replace if() with #if when checking version

[Yury Norov <ynorov@caviumnetworks.com>]

__fxstat() is always passed with _STAT_VER as vers parameter and it's
in internal namespace.

It means we can replace runtime argument check with compile-time #ifdef.
It helps to make the body of _fxstat() smaller, and suppresses errors
if struct kernel_stat or __xstat_conv() is not declared, when they
are not needed.

If patch is found reasonable, I can check and fix other platforms and
stat syscalls. Could someone explain me, what for we need 'vers',
if we pass it with the only value everywhere. Maybe it's time to remove it
completely?

	* sysdeps/unix/sysv/linux/fxstat.c: Replace if() with #if
	when checking version

Signed-off-by: Yury Norov <ynorov@caviumnetworks.com>
---
 sysdeps/unix/sysv/linux/fxstat.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/sysdeps/unix/sysv/linux/fxstat.c b/sysdeps/unix/sysv/linux/fxstat.c
index e33023b..2e79f8b 100644
--- a/sysdeps/unix/sysv/linux/fxstat.c
+++ b/sysdeps/unix/sysv/linux/fxstat.c
@@ -35,20 +35,22 @@
 int
 __fxstat (int vers, int fd, struct stat *buf)
 {
-  if (vers == _STAT_VER_KERNEL)
-    return INLINE_SYSCALL (fstat, 2, fd, buf);
+#if _STAT_VER == _STAT_VER_KERNEL
+  return INLINE_SYSCALL (fstat, 2, fd, buf);
+#else
 
-#ifdef STAT_IS_KERNEL_STAT
+# ifdef STAT_IS_KERNEL_STAT
   return INLINE_SYSCALL_ERROR_RETURN_VALUE (EINVAL);
-#else
+# else
   struct kernel_stat kbuf;
   int result;
 
   result = INLINE_SYSCALL (fstat, 2, fd, &kbuf);
   if (result == 0)
-    result = __xstat_conv (vers, &kbuf, buf);
+    result = __xstat_conv (_STAT_VER, &kbuf, buf);
 
   return result;
+# endif
 #endif
 }
 
-- 
2.7.4