uml: rename os_{read_write}_file_k back to os_{read_write}_file

Rename os_{read_write}_file_k back to os_{read_write}_file, delete
the originals and their bogus infrastructure, and fix all the callers.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/um/kernel/sigio.c b/arch/um/kernel/sigio.c
index f756e78..89f9866 100644
--- a/arch/um/kernel/sigio.c
+++ b/arch/um/kernel/sigio.c
@@ -21,7 +21,7 @@
 {
 	char c;
 
-	os_read_file_k(sigio_irq_fd, &c, sizeof(c));
+	os_read_file(sigio_irq_fd, &c, sizeof(c));
 	reactivate_fd(sigio_irq_fd, SIGIO_WRITE_IRQ);
 	return IRQ_HANDLED;
 }