broadcom-wl: don't inherit lock descriptor in nas process

Add a local hack to prevent the Broadcom WPA authenticator process from
inheriting the lock descriptor 1000 used to prevent concurrent executions
of the init script.

Without this fix, repeated invocations of /etc/init.d/network, e.g. for
obtaining the enabled state, would hang forever.

Signed-off-by: Jo-Philipp Wich <jo@mein.io>

package/kernel/broadcom-wl/files/lib/wifi/broadcom.sh

@@ -443,7 +443,10 @@ EOF
 	txpower=${txpower:-$vif_txpower}
 	[ -z "$txpower" ] || iwconfig $device txpower ${txpower}dBm
 
-	eval "$nas_cmd"
+	# fd 1000 is an inherited lock file descriptor for preventing concurrent
+	# init script executions. Close it here to prevent the nas daemon from
+	# inheriting it further to avoid holding the lock indefinitely.
+	eval "$nas_cmd 1000>&-"
 }