[COVERITY] Fix file handle leak in debugfs's logdump (in error case)

Also fixed a bug in checking if the fopen failed.

Coverity ID: 30: Resource Leak

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2 files changed