scripts/renamepatches: Optimize search
    
    Use bash hashmap instead of grepping list file.
    
    sample:
    5.0s -> 2.5s
    
    Composed result with previous commit on SLE15-SP4->SLE15-SP5:
    original
    Executed in  207.82 secs    fish           external
       usr time  263.64 secs  459.00 micros  263.64 secs
       sys time   60.61 secs  185.00 micros   60.61 secs
    
    optimized
    Executed in   65.73 secs    fish           external
       usr time   49.16 secs  639.00 micros   49.16 secs
       sys time   18.52 secs    0.00 micros   18.52 secs