[lcms] Fix context leak on error path in cms_postscript_fuzzer

[OwenSanzas]

Summary

This is not a bug in lcms. It is a bug in cms_postscript_fuzzer where cmsDeleteContext is not called when cmsOpenProfileFromMem fails.

Bug Details (P1: Harness Logic)

cmsContext context = cmsCreateContext(NULL, (void *)data);  // line 22
if (!context) return 0;

cmsHPROFILE hProfile = cmsOpenProfileFromMem(data, size);
if (!hProfile){
    return 0;    // ← BUG: context leaked
}
// ... normal path correctly calls cmsDeleteContext(context)

Impact

Since most random fuzz inputs are not valid ICC profiles, cmsOpenProfileFromMem fails on the majority of iterations. This makes the context leak high-frequency — contexts accumulate rapidly in lcms2's global linked list, causing unbounded memory growth and performance degradation.

Suggested Fix

     if (!hProfile){
+        cmsDeleteContext(context);
         return 0;
     }

Coverage Comparison

Version	Lines	Functions
Original	27.00%	39.06%
Fixed	27.00%	39.06%

Coverage unchanged — fix does not regress fuzzer effectiveness.