drm/vc4: fix krealloc() memory leak

In the Linux kernel, the following vulnerability has been resolved: drm/vc4: fix krealloc() memory leak Don't just overwrite the original pointer passed to krealloc() with its return value without checking latter: MEM = krealloc(MEM, SZ, GFP); If krealloc() returns NULL, that erases the pointer to the still allocated memory, hence leaks this memory. Instead, use a temporary variable, check it's not NULL and only then assign it to the original pointer: TMP = krealloc(MEM, SZ, GFP); if (!TMP) return; MEM = TMP; While on it, use krealloc_array().