[lcms] Fix unused context leak and wrong return value in cms_cgats_fuzzer

[OwenSanzas]

Summary

This is not a bug in lcms. It is a bug in cms_cgats_fuzzer with two issues:

1. Unused context leak: cmsCreateContext called at line 23 but the context is never used or freed
2. Wrong return value: return 1 on the normal exit path (line 75) instead of return 0

Bug Details

Issue 1: Unused context (P1)

cmsContext context = cmsCreateContext(NULL, (void *)data);  // line 23
// context is NEVER used — all cmsIT8* calls use 0 (NULL/global context):
it8 = cmsIT8Alloc(0);                      // line 32 — uses global context
it8 = cmsIT8LoadFromFile(0, "TEST.IT8");   // line 66 — uses global context
// context is NEVER freed — no cmsDeleteContext anywhere

Issue 2: Wrong return value (P1)

cmsIT8Free(it8);
return 1;  // line 75 — should be return 0

LLVMFuzzerTestOneInput must return 0 per the libFuzzer contract. Non-zero returns are reserved for special semantics (e.g., -1 means "don't add to corpus" in some versions).

Suggested Fix

Remove the unused cmsCreateContext call and change return 1 to return 0.

Coverage Comparison

Version	Lines	Functions
Original	5.55%	9.78%
Fixed	4.57%	7.44%

Coverage decreased slightly — the removed cmsCreateContext call was contributing dead coverage of context internals, not meaningful testing.