[PATCH] Common compat_sys_sysinfo

I noticed that almost all architectures implemented exactly the same
sys32_sysinfo...  except parisc, where a bug was to be found in handling of
the uptime.  So let's remove a whole whack of code for fun and profit.
Cribbed compat_sys_sysinfo from x86_64's implementation, since I figured it
would be the best tested.

This patch incorporates Arnd's suggestion of not using set_fs/get_fs, but
instead extracting out the common code from sys_sysinfo.

Cc: Christoph Hellwig <hch@infradead.org>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index e1a429a..7e86130 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -313,6 +313,9 @@
 	(void)__tmp; \
 })
 
+struct sysinfo;
+extern int do_sysinfo(struct sysinfo *info);
+
 #endif /* __KERNEL__ */
 
 #define SI_LOAD_SHIFT	16