db_bench should fail on bad values for --compaction_fadvice and --value_size_distribution_type (#9741)

Summary:
db_bench quietly parses and ignores bad values for --compaction_fadvice and --value_size_distribution_type
I prefer that it fail for them as it does for bad option values in most other cases. Otherwise a benchmark
result will be provided for the wrong configuration and the result will be misleading.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9741

Test Plan:
These now fail:
./db_bench --compaction_fadvice=noney
Unknown compaction fadvice:noney

./db_bench --value_size_distribution_type=norma
Cannot parse distribution type 'norma'

While correct values continue to work:
 ./db_bench --value_size_distribution_type=normal
Initializing RocksDB Options from the specified file
Initializing RocksDB Options from command-line flags

./db_bench --compaction_fadvice=none
Initializing RocksDB Options from the specified file
Initializing RocksDB Options from command-line flags

Reviewed By: siying

Differential Revision: D35115973

Pulled By: mdcallag

fbshipit-source-id: c2b10de5c2d1ea7c7539e676f5bd556351f5d370

tools/db_bench_tool.cc

@@ -1644,7 +1644,7 @@ static enum DistributionType StringToDistributionType(const char* ctype) {
     return kNormal;
 
   fprintf(stdout, "Cannot parse distribution type '%s'\n", ctype);
-  return kFixed;  // default value
+  exit(1);
 }
 
 class BaseDistribution {
@@ -8119,6 +8119,7 @@ int db_bench_tool(int argc, char** argv) {
   else {
     fprintf(stdout, "Unknown compaction fadvice:%s\n",
             FLAGS_compaction_fadvice.c_str());
+    exit(1);
   }
 
   FLAGS_value_size_distribution_type_e =