vendor.sh: properly call err_ in fail_inject

i can't call $err (variable), because it's set
to fail_inject. fix this infinite loop, which
was an oversight in the previous commit.

Signed-off-by: Leah Rowe <leah@libreboot.org>

include/vendor.sh

@@ -337,7 +337,7 @@ fail_inject()
 	printf "\n\n%s\n\n" "$dontflash" 1>&2
 	printf "WARNING: File '%s' was NOT modified.\n\n" "$archive" 1>&2
 	printf "Please MAKE SURE vendor files are inserted before flashing\n\n"
-	$err "$1"
+	err_ "$1"
 }
 
 vendor_inject()