This little change does fix a verbose+dangerous warning

[ebachard]

Hello,

Building x264 code on Linux Intel (x86_64) caused a long warning. This fix is a suggestion to fix the issue (see the log below)

Feel free to accept (or not this change) under MIT license (ask me something else if you need).

Thanks a lot for sharing the code, and thank you very much for providing such features :-)

Eric Bachard

The log containing the warning:

encoder/rdo.c: In function ‘x264_8_quant_8x8_trellis’:
encoder/rdo.c:1088:13: warning: assuming signed overflow does not occur when assuming that (X + c) >= X is always true [-Wstrict-overflow]
             for( i = start; i <= end; i+=step )
             ^~~
encoder/rdo.c:1088:13: warning: assuming signed overflow does not occur when assuming that (X + c) >= X is always true [-Wstrict-overflow]
encoder/rdo.c:1088:13: warning: assuming signed overflow does not occur when assuming that (X + c) >= X is always true [-Wstrict-overflow]
encoder/rdo.c:1088:13: warning: assuming signed overflow does not occur when assuming that (X + c) >= X is always true [-Wstrict-overflow]
encoder/rdo.c:1088:13: warning: assuming signed overflow does not occur when assuming that (X + c) >= X is always true [-Wstrict-overflow]
encoder/rdo.c:1088:13: warning: assuming signed overflow does not occur when assuming that (X + c) >= X is always true [-Wstrict-overflow]
encoder/rdo.c:1088:13: warning: assuming signed overflow does not occur when assuming that (X + c) >= X is always true [-Wstrict-overflow]
encoder/rdo.c:1088:13: warning: assuming signed overflow does not occur when assuming that (X + c) >= X is always true [-Wstrict-overflow]
encoder/rdo.c:1088:13: warning: assuming signed overflow does not occur when assuming that (X + c) >= X is always true [-Wstrict-overflow]
encoder/rdo.c:1088:13: warning: assuming signed overflow does not occur when assuming that (X + c) >= X is always true [-Wstrict-overflow]
encoder/rdo.c:1088:13: warning: assuming signed overflow does not occur when assuming that (X + c) >= X is always true [-Wstrict-overflow]
encoder/rdo.c:1088:13: warning: assuming signed overflow does not occur when assuming that (X + c) >= X is always true [-Wstrict-overflow]
encoder/rdo.c:1088:13: warning: assuming signed overflow does not occur when assuming that (X + c) >= X is always true [-Wstrict-overflow]
encoder/rdo.c:1088:13: warning: assuming signed overflow does not occur when assuming that (X + c) >= X is always true [-Wstrict-overflow]
encoder/rdo.c:1088:13: warning: assuming signed overflow does not occur when assuming that (X + c) >= X is always true [-Wstrict-overflow]