Fix eqlx CLI output parsing on bad input

Fix eqlx CLI output parsing on bad input

The eqlx driver would identify CLI command completion
by looking for the system name prompt at the end of
the output ("ARRAY_NAME>"). In some cases where there
is bad input the array will print an error, then
prepopulate the command again so it can be edited,
resulting in the output:

"ARRAY_NAME> [bad command]"

The array name prompt only gets printed on command
completion, so the fix is to look for the prompt
anywhere in the CLI output.

Change-Id: I063a203c9746689ca8a42a97725b059f782e3812
Closes-Bug: 1378394