Coverity 400477: pcre_get_substring retval

Add missing return code check to pcre_get_substring call.
Coverity 1038089: error check fseek call
Coverity 1038094: remove dead code from defrag hash
Coverity 1038095: remove dead code from defrag hash timeout code
Coverity 1038098: remove dead code from flow hash
Coverity 1038099: remove dead code from flow hash timeout code
Coverity 1038100: remove dead code from flow hash timeout code(2)
Coverity 1038101: remove dead code from host hash timeout code
Coverity 1038102: remove dead code from host hash