test: make sure temp files are cleaned up on test_tpm2_nv.sh exit
test: make sure temp files are cleaned up on test_tpm2_nv.sh exit

If the test is interrupted, then temporary files may not be cleaned up
correctly. Ensure that the files are always removed on the script exit.

Signed-off-by: Javier Martinez Canillas <8fdf2abf85d34ea8f3f979ef25dc1f25d94aca29@redhat.com>

martinezjavier/tpm2-tools,01org/tpm2.0-tools,01org/tpm2.0-tools,martinezjavier/tpm2-tools,martinezjavier/tpm2-tools,01org/tpm2.0-tools,martinezjavier/tpm2-tools