Test writes outside array bounds

[MartinCowen]

In cobs_test.c, line 124

COBS-Consistent-Overhead-Byte-Stuffing/cobs_test.c

Line 124 in c4876cc

expected_buffer[257] = 0xAB;

expected_buffer[257] = 0xAB;

in test_255_bytes_null_end. The buffer is declared with 257 elements, so has indexes 0 to 256:

uint8_t expected_buffer[257];