tpm2_nvread: fix input handling no nv index #1641

Job	Run time
coverity-test	0s
master-tss-build-test (gcc)	18m 8s
build-test (ubuntu-18.04, gcc)	5m 43s
master-tss-build-test (clang)	4m 58s
coverage-test	5m 56s
build-test (ubuntu-18.04, clang)	5m 4s
build-test (ubuntu-20.04, gcc)	6m 3s
build-test (ubuntu-20.04, clang)	4m 55s
build-test (fedora-30, gcc)	5m 46s
build-test (fedora-30, clang)	5m 20s
build-test (opensuse-leap, gcc)	6m 5s
build-test (opensuse-leap, clang)	5m 10s
build-test (fedora-32, gcc)	6m 2s
build-test (fedora-32, clang)	5m 6s
build-test (ubuntu-22.04, gcc)	11m 11s
build-test (ubuntu-22.04, clang)	10m 46s
	1h 46m 13s

Provide feedback