m68k: set proper major_num when specifying module param major_num

When calling register_blkdev() with specified major
device number, the return code is 0 on success.
So it seems not correct direct assign return code to
variable major_num in this case.

Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Chengguang Xu <cgxu519@gmx.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/arch/m68k/emu/nfblock.c b/arch/m68k/emu/nfblock.c
index 3804935..40712e4 100644 (file)
--- a/arch/m68k/emu/nfblock.c
+++ b/arch/m68k/emu/nfblock.c
@@ -155,18 +155,22 @@ out:
 static int __init nfhd_init(void)
 {
        u32 blocks, bsize;
+       int ret;
        int i;
 
        nfhd_id = nf_get_id("XHDI");
        if (!nfhd_id)
                return -ENODEV;
 
-       major_num = register_blkdev(major_num, "nfhd");
-       if (major_num <= 0) {
+       ret = register_blkdev(major_num, "nfhd");
+       if (ret < 0) {
                pr_warn("nfhd: unable to get major number\n");
-               return major_num;
+               return ret;
        }
 
+       if (!major_num)
+               major_num = ret;
+
        for (i = NFHD_DEV_OFFSET; i < 24; i++) {
                if (nfhd_get_capacity(i, 0, &blocks, &bsize))
                        continue;