log: fix log level regexp matching
log: fix log level regexp matching

Fix misuse of regular expression functions, which was producing a
segfault.

After the patch, it works properly:

  $ ./build/app/test --no-huge --log-level=pmd,3
  RTE>>dump_log_types
  [...]
  id 30: user7, level is debug
  id 31: user8, level is debug
  id 32: pmd.i40e.init, level is critical
  id 33: pmd.i40e.driver, level is critical

Coverity issue: 143472
Fixes: a5279180f510 ("eal: change several log levels matching a regexp")

Reported-by: Jianfeng Tan <4339d9ba3a87a0d192e405945005ff86667f7b0c@intel.com>
Signed-off-by: Olivier Matz <dfcc1510895413197abb4336e39bb0a3906cba71@6wind.com>
Acked-by: Ferruh Yigit <ba8734c3c506d2e3557bd4ac8fdaccd25bdb9aa7@intel.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk