[lldb] [Host/FreeBSD] Remove unused variable (NFC)

Author: mgorny

lldb/source/Host/freebsd/HostInfoFreeBSD.cpp

@@ -32,7 +32,6 @@ llvm::VersionTuple HostInfoFreeBSD::GetOSVersion() {
 
 llvm::Optional<std::string> HostInfoFreeBSD::GetOSBuildString() {
   int mib[2] = {CTL_KERN, KERN_OSREV};
-  char osrev_str[12];
   uint32_t osrev = 0;
   size_t osrev_len = sizeof(osrev);