fs: add ksys_close() wrapper; remove in-kernel calls to sys_close()

Using the ksys_close() wrapper allows us to get rid of in-kernel calls
to the sys_close() syscall. The ksys_ prefix denotes that this function
is meant as a drop-in replacement for the syscall. In particular, it
uses the same calling convention as sys_close(), with one subtle
difference:

The few places which checked the return value did not care about the return
value re-writing in sys_close(), so simply use a wrapper around
__close_fd().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>

1 files changed, 3 insertions, 3 deletions

diff --git a/init/do_mounts_rd.c b/init/do_mounts_rd.c
index 5b69056f610a..f1aa341862d3 100644
--- a/init/do_mounts_rd.c
+++ b/init/do_mounts_rd.c
@@ -257,7 +257,7 @@ int __init rd_load_image(char *from)
 		if (i && (i % devblocks == 0)) {
 			printk("done disk #%d.\n", disk++);
 			rotate = 0;
-			if (sys_close(in_fd)) {
+			if (ksys_close(in_fd)) {
 				printk("Error closing the disk.\n");
 				goto noclose_input;
 			}
@@ -283,9 +283,9 @@ int __init rd_load_image(char *from)
 successful_load:
 	res = 1;
 done:
-	sys_close(in_fd);
+	ksys_close(in_fd);
 noclose_input:
-	sys_close(out_fd);
+	ksys_close(out_fd);
 out:
 	kfree(buf);
 	ksys_unlink("/dev/ram");