m68k: Replace memcpy() + manual NUL-termination with strscpy()

Use strscpy() to safely copy the command-line string instead of memcpy()
followed by a manual NUL-termination.

The source string is also NUL-terminated and meets the __must_be_cstr()
requirement of strscpy().

No functional changes intended.

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>

Author: toblux

arch/m68k/kernel/setup_no.c

@@ -145,8 +145,7 @@ void __init setup_arch(char **cmdline_p)
 
 	/* Keep a copy of command line */
 	*cmdline_p = &command_line[0];
-	memcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
-	boot_command_line[COMMAND_LINE_SIZE-1] = 0;
+	strscpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
 
 	/*
 	 * Give all the memory to the bootmap allocator, tell it to put the