Simplify flash.c

[dbrgn]

The manual for-loop looked a bit funny :)

(A memcpy would probably work as well, but is less easy to read and also results in a larger binary.)

[hannobraun]

Thanks!

Did you call compile.sh? If it generates different code, we should update the binary also.

[dbrgn]

On master:

$ ./compile.sh && sha1sum libflash.a
0f720d2f86e55e2fe2e05bc639c18eef595a45fa  libflash.a

On this branch:

$ ./compile.sh && sha1sum libflash.a
0f720d2f86e55e2fe2e05bc639c18eef595a45fa  libflash.a

...so I didn't commit the rebuilt binary, especially considering that the checked-in binary is 896 bytes, while the one my compiler generates is 900 bytes. Probably because a different gcc version was used.

[hannobraun]

Makes sense, thank you.