fix(inputs.smart): Improve regexp to support flags with a plus

[Akito0723]

change attribute regexp to support flags like this kind PO-RC-+

Summary

support smart attitudes data like this

SMART Attributes Data Structure revision number: 16
Vendor Specific SMART Attributes with Thresholds:
ID# ATTRIBUTE_NAME          FLAGS    VALUE WORST THRESH FAIL RAW_VALUE
  1 Raw_Read_Error_Rate     PO-RC-+  200   200   051    -    30
  3 Spin_Up_Time            POSRCK+  230   230   021    -    5466
  4 Start_Stop_Count        -OS-CK+  100   100   000    -    6
  5 Reallocated_Sector_Ct   POS-C-+  200   200   140    -    0
  7 Seek_Error_Rate         PO-RCK+  200   200   051    -    0
  9 Power_On_Hours          -OSRCK+  092   092   000    -    5867
 10 Spin_Retry_Count        POS-CK+  100   253   051    -    0
 11 Calibration_Retry_Count -OSRCK+  100   253   051    -    0
 12 Power_Cycle_Count       -OSRCK+  100   100   000    -    6
184 End-to-End_Error        POSRCK+  100   100   097    -    0
187 Reported_Uncorrect      -OS-CK+  100   088   000    -    24
188 Command_Timeout         -OS--K+  100   100   000    -    0
190 Airflow_Temperature_Cel -O-RCK+  058   046   000    -    42
192 Power-Off_Retract_Count -O-RCK+  200   200   000    -    4
193 Load_Cycle_Count        --S-CK+  200   200   000    -    2
194 Temperature_Celsius     -OSRCK+  110   098   000    -    42
195 Hardware_ECC_Recovered  -OSRC-+  200   200   000    -    0
196 Reallocated_Event_Count -O-RCK+  200   200   000    -    0
197 Current_Pending_Sector  -OS-CK+  200   200   000    -    0
198 Offline_Uncorrectable   -OSRCK+  100   253   000    -    0
199 UDMA_CRC_Error_Count    -OS--K+  200   200   000    -    0
200 Multi_Zone_Error_Rate   POSRCK+  100   253   051    -    0
                            ||||||_ K auto-keep
                            |||||__ C event count
                            ||||___ R error rate
                            |||____ S speed/performance
                            ||_____ O updated online
                            |______ P prefailure warning

Checklist

• No AI generated code was used in this PR

Related issues

resolves #14995

[telegraf-tiger]

Thanks so much for the pull request!
🤝 ✒️ Just a reminder that the CLA has not yet been signed, and we'll need it before merging. Please sign the CLA when you get a chance, then post a comment here saying !signed-cla

[srebhan]

@Akito0723 can you please confirm that you didn't use any AI to produce the code by ticking the box in the PR description!?!

[srebhan]

Thanks for your contribution @Akito0723!