Fix "log_sev uninitialized" warning in lib/switchtec
Fix "log_sev uninitialized" warning in lib/switchtec

Warning message:
lib/switchtec.c: In function write_parsed_loog
lib/switchtec.c:1039:8: warning: log_sev may be used uninitialized in this function [-Wmaybe-uninitialized]

Microsemi/switchtec-user,Microsemi/switchtec-user