test: fix format-truncation warnings

This patchset addresses the -Wformat-truncation warnings throughout the DPDK test suite, allowing the warning to be re-enabled.

The changes include:
- Properly sizing buffers using named constants (RTE_MEMZONE_NAMESIZE, NAME_MAX)
- Adding a common file_prefix_arg() helper to reduce code duplication
- Using standard library functions (getmntent) for mount parsing
- Checking snprintf() return values for potential truncation
- Converting problematic 2D arrays to pointer arrays

After these fixes, the final patch removes -Wno-format-truncation from the test build flags, ensuring these issues are caught in the future.

Several patches are marked for stable backport where they fix real potential bugs rather than just theoretical compiler warnings.

v12 - rebase to handle new eal_flags printf's

Stephen Hemminger (8):
test: increase size of memzone name
test: add new function to get current file-prefix arg
test: avoid overflowing huge directory path
test: fix format overflow warning in ACL test
test: fix impossible format-truncation in cfgfiles
test: fix format overflow in cryptodev test
test: fix overflow warnings in common code
test: re-enable format-truncation warnings

 app/test/meson.build            |   1 -
 app/test/process.h              |  44 ++++--
 app/test/test_cfgfile.c         |   8 +-
 app/test/test_cryptodev.c       |  22 ++-
 app/test/test_eal_flags.c       | 269 +++++++++++---------------------
 app/test/test_memzone.c         |   2 +-
 app/test/test_mp_secondary.c    |  14 +-
 app/test/test_pdump.c           |  13 +-
 app/test/test_table_acl.c       |  30 ++--
 app/test/test_timer_secondary.c |  12 +-
 10 files changed, 174 insertions(+), 241 deletions(-)

2.51.0