block: don't return -EINVAL for not found names in devt_from_devname

When we didn't find a device and didn't guess it might be a partition,
it might still show up later, so don't disable rootwait for it by
returning -EINVAL.

Fixes: 079caa35 ("init: clear root_wait on all invalid root= strings")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230622150644.600327-1-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

block/early-lookup.c

@@ -175,7 +175,7 @@ static int __init devt_from_devname(const char *name, dev_t *devt)
 	while (p > s && isdigit(p[-1]))
 		p--;
 	if (p == s || !*p || *p == '0')
-		return -EINVAL;
+		return -ENODEV;
 
 	/* try disk name without <part number> */
 	part = simple_strtoul(p, NULL, 10);
@@ -186,7 +186,7 @@ static int __init devt_from_devname(const char *name, dev_t *devt)
 
 	/* try disk name without p<part number> */
 	if (p < s + 2 || !isdigit(p[-2]) || p[-1] != 'p')
-		return -EINVAL;
+		return -ENODEV;
 	p[-1] = '\0';
 	*devt = blk_lookup_devt(s, part);
 	if (*devt)