[Fix](MemtableMemoryLimiter) Fix memtable memory limiter tigger flush log

[sollhui]

Proposed changes

Fix memtable memory limiter tigger flush log, "reached the load hard limit" is error.

Further comments

If this is a relatively large or complex change, kick off the discussion at dev@doris.apache.org by explaining why you chose the solution you did and what alternatives you considered, etc...

[sollhui]

run buildall

[github-actions]

clang-tidy review says "All clean, LGTM! 👍"

[doris-robot]

(From new machine)TeamCity pipeline, clickbench performance test result:
the sum of best hot time: 49.4 seconds
stream load tsv: 534 seconds loaded 74807831229 Bytes, about 133 MB/s
stream load json: 20 seconds loaded 2358488459 Bytes, about 112 MB/s
stream load orc: 64 seconds loaded 1101869774 Bytes, about 16 MB/s
stream load parquet: 31 seconds loaded 861443392 Bytes, about 26 MB/s
insert into select: 28.9 seconds inserted 10000000 Rows, about 346K ops/s
storage size: 17161940621 Bytes

[dataroaring]

LGTM

[github-actions]

PR approved by at least one committer and no changes requested.

[github-actions]

PR approved by anyone and no changes requested.

[sollhui]

run buildall

[github-actions]

clang-tidy review says "All clean, LGTM! 👍"

[doris-robot]

TeamCity be ut coverage result:
Function Coverage: 36.94% (7911/21415)
Line Coverage: 28.96% (63554/219446)
Region Coverage: 27.90% (32997/118282)
Branch Coverage: 24.47% (16953/69276)
Coverage Report: http://coverage.selectdb-in.cc/coverage/f99e8f2d001104dd6eb1cf52163a5661ad472cad_f99e8f2d001104dd6eb1cf52163a5661ad472cad/report/index.html

[doris-robot]

(From new machine)TeamCity pipeline, clickbench performance test result:
the sum of best hot time: 48.73 seconds
stream load tsv: 584 seconds loaded 74807831229 Bytes, about 122 MB/s
stream load json: 20 seconds loaded 2358488459 Bytes, about 112 MB/s
stream load orc: 64 seconds loaded 1101869774 Bytes, about 16 MB/s
stream load parquet: 32 seconds loaded 861443392 Bytes, about 25 MB/s
insert into select: 29.1 seconds inserted 10000000 Rows, about 343K ops/s
storage size: 17162188035 Bytes

[dataroaring]

LGTM