m68k: Move from strlcpy with unused retval to strscpy

Follow the advice of the below link and prefer 'strscpy' in this
subsystem. Conversion is 1:1 because the return value is not used.
Generated by a coccinelle script.

Link: https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://lore.kernel.org/r/20220818205941.6240-1-wsa+renesas@sang-engineering.com
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>

Author: Wolfram Sang

arch/m68k/kernel/setup_mm.c

@@ -148,7 +148,7 @@ static void __init m68k_parse_bootinfo(const struct bi_record *record)
 			break;
 
 		case BI_COMMAND_LINE:
-			strlcpy(m68k_command_line, data,
+			strscpy(m68k_command_line, data,
 				sizeof(m68k_command_line));
 			break;