[PATCH] uml: error handling fixes

Blairsorblade noticed some confusion between our use of a system
call's return value and errno.  This patch fixes a number of related
bugs -
	using errno instead of a return value
	using a return value instead of errno
	forgetting to negate a error return to get a positive error code

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/um/os-Linux/file.c

@@ -171,7 +171,7 @@ int os_sigio_async(int master, int slave)
 
 	flags = fcntl(master, F_GETFL);
 	if(flags < 0)
-		return errno;
+		return -errno;
 
 	if((fcntl(master, F_SETFL, flags | O_NONBLOCK | O_ASYNC) < 0) ||
 	   (fcntl(master, F_SETOWN, os_getpid()) < 0))