uml: userspace files should call libc directly

A number of files that were changed in the recent removal of tt mode
are userspace files which call the os_* wrappers instead of calling
libc directly.  A few other files were affected by this, through

This patch makes these call glibc directly.

There are also style fixes in the affected areas.

os_print_error has no remaining callers, so it is deleted.

There is a interface change to os_set_exec_close, eliminating a
parameter which was always the same.  The callers are fixed as well.

os_process_pc got its error path cleaned up.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/um/os-Linux/aio.c

@@ -226,8 +226,8 @@ static int init_aio_24(void)
 	goto out;
 
 out_close_pipe:
-	os_close_file(fds[0]);
-	os_close_file(fds[1]);
+	close(fds[0]);
+	close(fds[1]);
 	aio_req_fd_w = -1;
 	aio_req_fd_r = -1;
 out: