comgt: ncm: strip CR when detecting the modem on teardown

proto_ncm_setup() parses the AT+CGMI reply with RS='\r?\n',
proto_ncm_teardown() does not. The manufacturer ends up as "quectel\r",
json_select fails with "Unsupported modem" and teardown returns before
sending the disconnect command, leaving the data call up on the modem.

A blank CRLF line hits the same path: \r is not whitespace for the
default FS, so a record holding only \r still has NF == 1 and is taken
as the manufacturer.

This affects every vendor whose reply is a single token. "zte" comes out
the same either way, its reply is "ZTE INCORPORATED" so the CR sits past
$1.

Note that teardown now reaches the disconnect command on modems where it
silently never did, so those commands actually get sent on ifdown.

Signed-off-by: Carlo Szelinsky <github@szelinsky.de>
Link: https://github.com/openwrt/openwrt/pull/24689
Signed-off-by: Jonas Jelonek <jonas@jonasjelonek.de>

package/network/utils/comgt/Makefile

@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=comgt
 PKG_VERSION:=0.32
-PKG_RELEASE:=36
+PKG_RELEASE:=37
 
 PKG_SOURCE:=$(PKG_NAME).$(PKG_VERSION).tgz
 PKG_SOURCE_URL:=@SF/comgt

package/network/utils/comgt/files/ncm.sh

@@ -263,7 +263,7 @@ proto_ncm_teardown() {
 	json_get_vars manufacturer
 	[ $? -ne 0 -o -z "$manufacturer" ] && {
 		# Fallback to direct detect, for proper handle device replug.
-		manufacturer=$(gcom -d "$device" -s /etc/gcom/getcardinfo.gcom | awk 'NF && $0 !~ /AT\+CGMI/ { sub(/\+CGMI: /,""); print tolower($1); exit; }')
+		manufacturer=$(gcom -d "$device" -s /etc/gcom/getcardinfo.gcom | awk -v RS='\r?\n' 'NF && $0 !~ /AT\+CGMI/ { sub(/\+CGMI: /,""); print tolower($1); exit; }')
 		[ $? -ne 0 -o -z "$manufacturer" ] && {
 			echo "Failed to get modem information"
 			proto_notify_error "$interface" GETINFO_FAILED