dp_rte_flow_helpers: Explicit array initialization

[mkalcok]

GCC 15 introduces 'unterminated-string-initialization'[0] warning and since we treat warning as errors in our builds, we might as well get ahead of the issue and change from string literals to explicit array initialization.

[0] https://gcc.gnu.org/cgit/gcc/commit/?id=44c9403ed1833ae71a59e84f9e37af3182be0df5

Proposed Changes

• Use explicit byte array initialization instead of string literals.

[PlagueCZ]

Makes sense.

But needs to be tested to be 100% sure, because this is offloading related and thus test suite is not able to test this.

[PlagueCZ]

So I tested it and this is a no-op change.

Methodology (thank you Claude):

git switch main
ninja -C build
objdump -s -j .rodata build/src/dpservice-bin >/tmp/pre
git switch explicit-array-init
ninja -C build
objdump -s -j .rodata build/src/dpservice-bin >/tmp/post
diff /tmp/pre /tmp/post

This results in a diff with only the git hash changing:

4098,4099c4098,4099
<  224fd0 302e332e 32322d38 2d673662 33616132  0.3.22-8-g6b3aa2
<  224fe0 39300000 00000000 476f7420 696e7661  90......Got inva
---
>  224fd0 302e332e 32322d39 2d676534 35643837  0.3.22-9-ge45d87
>  224fe0 30350000 00000000 476f7420 696e7661  05......Got inva
9563,9564c9563,9564
<  23a560 302e332e 32322d38 2d673662 33616132  0.3.22-8-g6b3aa2
<  23a570 39300044 50205365 72766963 65207665  90.DP Service ve
---
>  23a560 302e332e 32322d39 2d676534 35643837  0.3.22-9-ge45d87
>  23a570 30350044 50205365 72766963 65207665  05.DP Service ve
11145c11145
<  240840 2e32322d 382d6736 62336161 32393000  .22-8-g6b3aa290.
---
>  240840 2e32322d 392d6765 34356438 37303500  .22-9-ge45d8705.

To double check (the test and the AI):

# edit include/rte_flow/dp_rte_flow_helpers.h and replace single 0xff with 0xfe
ninja -C build
objdump -s -j .rodata build/src/dpservice-bin >/tmp/post
diff /tmp/pre /tmp/post

this results in

$ diff /tmp/pre /tmp/post
8492c8492
<  236270 ffffffff ffff0000 00000000 ffff0000  ................
---
>  236270 ffffffff fffe0000 00000000 ffff0000  ................
8598c8598
<  236910 ffffffff ffff0000 00000000 ffff0000  ................
---
>  236910 ffffffff fffe0000 00000000 ffff0000  ................
8790c8790
<  237510 ffffffff ffff0000 00000000 ffff0000  ................
---
>  237510 ffffffff fffe0000 00000000 ffff0000  ................
8940c8940
<  237e70 ffffffff ffff0000 00000000 ffff0000  ................
---
>  237e70 ffffffff fffe0000 00000000 ffff0000  ................
9036c9036
<  238470 ffffffff ffff0000 00000000 ffff0000  ................
---
>  238470 ffffffff fffe0000 00000000 ffff0000  ................
9234c9234
<  2390d0 ffffffff ffff0000 00000000 ffff0000  ................
---
>  2390d0 ffffffff fffe0000 00000000 ffff0000  ................

[PlagueCZ]

Creates no change in generated machine code. LGTM