nios2: force the string buffer NULL-terminated

strncpy() does not ensure NULL-termination when the input string
size equals to the destination buffer size COMMAND_LINE_SIZE.
Besides, grep under arch/ with 'boot_command_line' shows
no other arch-specific code uses strncpy() when copying
boot_command_line.

Use strlcpy() instead.

This issue is identified by a Coccinelle script.
Signed-off-by: Wang Xiayang <xywang.sjtu@sjtu.edu.cn>
Signed-off-by: Ley Foon Tan <ley.foon.tan@intel.com>

arch/nios2/kernel/setup.c

@@ -123,7 +123,7 @@ asmlinkage void __init nios2_boot_init(unsigned r4, unsigned r5, unsigned r6,
 		dtb_passed = r6;
 
 		if (r7)
-			strncpy(cmdline_passed, (char *)r7, COMMAND_LINE_SIZE);
+			strlcpy(cmdline_passed, (char *)r7, COMMAND_LINE_SIZE);
 	}
 #endif
 
@@ -131,10 +131,10 @@ asmlinkage void __init nios2_boot_init(unsigned r4, unsigned r5, unsigned r6,
 
 #ifndef CONFIG_CMDLINE_FORCE
 	if (cmdline_passed[0])
-		strncpy(boot_command_line, cmdline_passed, COMMAND_LINE_SIZE);
+		strlcpy(boot_command_line, cmdline_passed, COMMAND_LINE_SIZE);
 #ifdef CONFIG_NIOS2_CMDLINE_IGNORE_DTB
 	else
-		strncpy(boot_command_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
+		strlcpy(boot_command_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
 #endif
 #endif