Some tests (like TEST-02) set a multiline string to $KERNEL_APPEND
(which is a valid thing to do), unfortunately we'd use only the first
line of it and throw the rest away, e.g:
```
$ printf "%s" "$x"
hello
this is a multiline
kernel command line
$ read -ra out <<< "$x"
$ printf "%s" "${out[@]}"
hello
```
Let's use readarray/mapfile instead to avoid this:
```
$ readarray out <<< "$x"
$ printf "%s" "${out[@]}"
hello
this is a multiline
kernel command line
```
if [[ -n "${KERNEL_APPEND:=}" ]]; then
local user_kernel_append
- read -ra user_kernel_append <<< "$KERNEL_APPEND"
+ readarray user_kernel_append <<< "$KERNEL_APPEND"
kernel_params+=("${user_kernel_append[@]}")
fi
if [[ -n "${KERNEL_APPEND:=}" ]]; then
local user_kernel_append
- read -ra user_kernel_append <<< "$KERNEL_APPEND"
+ readarray user_kernel_append <<< "$KERNEL_APPEND"
kernel_params+=("${user_kernel_append[@]}")
fi