Fix cache_009_pos test on sm4u-2.

• Fix issues with verify_cache_device():
• Don't assume the device name is at most 3 characters long.
• While here, clean up the awk script so it is more legible.
• cleanup: Dump the final pool configurations if they exist, for all

	  tests in this suite.

Submitted by: Will
Sponsored by: Spectra Logic Corp