[openwrt/openwrt] scripts/env: fix remaining shellcheck warning

[LEDE Commits]

ynezz pushed a commit to openwrt/openwrt.git, branch master:
https://git.openwrt.org/227e47b3ca964939f41c3564dd7da72d60044d00

commit 227e47b3ca964939f41c3564dd7da72d60044d00
Author: Petr Štetiar <ynezz at true.cz>
AuthorDate: Sat Jul 11 13:20:34 2020 +0200

    scripts/env: fix remaining shellcheck warning
    
    Fixes following shellcheck warning:
    
     In scripts/env line 25:
            exit ${1:-1}
                 ^-----^ SC2086: Double quote to prevent globbing and word splitting.
    
    Signed-off-by: Petr Štetiar <ynezz at true.cz>
---
 scripts/env | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/env b/scripts/env
index c81fbf8ddc..726a354b57 100755
--- a/scripts/env
+++ b/scripts/env
@@ -22,7 +22,7 @@ Commands:
 Options:
 
 EOF
-	exit ${1:-1}
+	exit "${1:-1}"
 }
 
 error() {