COMP: Remove use of tmpnam

Use of tmpname causes an error on CentOS, as it is
considered dangerous. Replace with a hardcoded file
path for each testcase.

Change-Id: I2d7d6b45e6fff2aace9a581db243d90b27fe2d86
Merge topic 'hdf5-tmpnam-fix' into master

67cbc464 COMP: Remove use of tmpnam