Hexagon: 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] KSPP#89

Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230530162608.984333-1-azeemshaikh38@gmail.com

Author: azeemshaikh38

arch/hexagon/kernel/setup.c

@@ -66,17 +66,17 @@ void __init setup_arch(char **cmdline_p)
 		on_simulator = 0;
 
 	if (p[0] != '\0')
-		strlcpy(boot_command_line, p, COMMAND_LINE_SIZE);
+		strscpy(boot_command_line, p, COMMAND_LINE_SIZE);
 	else
-		strlcpy(boot_command_line, default_command_line,
+		strscpy(boot_command_line, default_command_line,
 			COMMAND_LINE_SIZE);
 
 	/*
 	 * boot_command_line and the value set up by setup_arch
 	 * are both picked up by the init code. If no reason to
 	 * make them different, pass the same pointer back.
 	 */
-	strlcpy(cmd_line, boot_command_line, COMMAND_LINE_SIZE);
+	strscpy(cmd_line, boot_command_line, COMMAND_LINE_SIZE);
 	*cmdline_p = cmd_line;
 
 	parse_early_param();