Memory leak in tpm_ascii_bios_measurements_open()

Coverity found a memory leak in tpm_ascii_bios_measurements_open().

If "read_log(log)" fails, then we may leak 'log' and
'log->bios_event_log'.

Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Cc: Seiji Munetoh <munetoh@jp.ibm.com>
Cc: Stefan Berger <stefanb@us.ibm.com>
Cc: Reiner Sailer <sailer@watson.ibm.com>
Cc: Kylene Hall <kjhall@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>