sh: Replace all non-returning strlcpy with strscpy

strlcpy() reads the entire source buffer first.
This read may exceed the destination size limit.
This is both inefficient and can lead to linear read
overflows if a source string is not NUL-terminated [1].
In an effort to remove strlcpy() completely [2], replace
strlcpy() here with strscpy().
No return values were used, so direct replacement is safe.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
[2] https://github.com/KSPP/linux/issues/89

Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
Acked-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Tested-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230530163041.985456-1-azeemshaikh38@gmail.com

arch/sh/drivers/dma/dma-api.c

@@ -198,7 +198,7 @@ int request_dma(unsigned int chan, const char *dev_id)
 	if (atomic_xchg(&channel->busy, 1))
 		return -EBUSY;
 
-	strlcpy(channel->dev_id, dev_id, sizeof(channel->dev_id));
+	strscpy(channel->dev_id, dev_id, sizeof(channel->dev_id));
 
 	if (info->ops->request) {
 		result = info->ops->request(channel);

arch/sh/kernel/setup.c

@@ -304,9 +304,9 @@ void __init setup_arch(char **cmdline_p)
 	bss_resource.end = virt_to_phys(__bss_stop)-1;
 
 #ifdef CONFIG_CMDLINE_OVERWRITE
-	strlcpy(command_line, CONFIG_CMDLINE, sizeof(command_line));
+	strscpy(command_line, CONFIG_CMDLINE, sizeof(command_line));
 #else
-	strlcpy(command_line, COMMAND_LINE, sizeof(command_line));
+	strscpy(command_line, COMMAND_LINE, sizeof(command_line));
 #ifdef CONFIG_CMDLINE_EXTEND
 	strlcat(command_line, " ", sizeof(command_line));
 	strlcat(command_line, CONFIG_CMDLINE, sizeof(command_line));