tests/int/*bats: ignore SC2016

Ignore the shellcheck warnings like this one:

> In tty.bats line 32:
> 	update_config '(.. | select(.[]? == "sh")) += ["-c", "stat -c %u:%g $(tty) | tr : \\\\n"]'
>                     ^-- SC2016: Expressions don't expand in single quotes, use double quotes for that.

While at it, fix some minor whitespace issues in tty.bats.

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>

tests/integration/checkpoint.bats

@@ -27,6 +27,7 @@ function teardown() {
 
 function setup_pipes() {
 	# The changes to 'terminal' are needed for running in detached mode
+	# shellcheck disable=SC2016
 	update_config 	' (.. | select(.terminal? != null)) .terminal |= false
 			| (.. | select(.[]? == "sh")) += ["-c", "for i in `seq 10`; do read xxx || continue; echo ponG $xxx; done"]'