Log correct compaction score for Universal Compaction (#11487)

Summary:
currently 0 is incorrectly logged as the compaction score for L0 when num_levels > 1. This PR fixes the issue to log the correct score.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11487

Test Plan:
```
./db_bench --benchmarks=fillrandom --max_background_jobs=8 --num=1000000  --compaction_style=1 --stats_dump_period_sec=20 --num_levels=7 --write_buffer_size=1048576

grep "L0   " /tmp/rocksdbtest-543376/dbbench/LOG

before:
** Compaction Stats [default] **
Priority    Files   Size     Score Read(GB)  Rn(GB) Rnp1(GB) Write(GB) Wnew(GB) Moved(GB) W-Amp Rd(MB/s) Wr(MB/s) Comp(sec) CompMergeCPU(sec) Comp(cnt) Avg(sec) KeyIn KeyDrop Rblob(GB) Wblob(GB)
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
L0      0/0    0.00 KB   0.0      0.0     0.0      0.0       0.0      0.0       0.0   1.0      0.0      9.9      0.42              0.33         9    0.046       0      0       0.0       0.0
L0      3/1    1.37 MB   0.0      0.0     0.0      0.0       0.0      0.0       0.0   1.1      0.6      9.6      3.76              3.03        76    0.050     34K    140       0.0       0.0
L0      2/0    2.26 MB   0.0      0.0     0.0      0.0       0.1      0.1       0.0   1.6      3.2      8.2     12.59             11.17       163    0.077    619K   5499       0.0       0.0

after: compaction scores are non-zero
L0      0/0    0.00 KB   0.8      0.0     0.0      0.0       0.0      0.0       0.0   1.0      0.0      9.6      0.43              0.34         9    0.048       0      0       0.0       0.0
L0      2/1   937.08 KB   1.0      0.0     0.0      0.0       0.0      0.0       0.0   1.1      0.6      9.3      3.85              3.07        75    0.051     34K    165       0.0       0.0
L0      2/2    1.82 MB   1.0      0.0     0.0      0.0       0.1      0.1       0.0   1.6      3.0      8.0     12.45             10.99       160    0.078    577K   5399       0.0       0.0

```

Reviewed By: ajkr

Differential Revision: D46293993

Pulled By: cbi42

fbshipit-source-id: 19753f7df68c5f54a84c4ed52794f83e510c9721

db/internal_stats.cc

@@ -1738,7 +1738,7 @@ void InternalStats::DumpCFMapStats(
   assert(vstorage);
 
   int num_levels_to_check =
-      (cfd_->ioptions()->compaction_style != kCompactionStyleFIFO)
+      (cfd_->ioptions()->compaction_style == kCompactionStyleLevel)
           ? vstorage->num_levels() - 1
           : 1;