swtpm: Handle case where unknown blobtype is given (Coverity)

Handle the case where an unknown blobtype is given and therefore
cannot be translated to a filename and blobname is NULL. Previously
this would have lead to an error when trying to read the file, now
we handle the failure case earlier.

Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
1 file changed