x86/mm: Check return value from memblock_phys_alloc_range()

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CVE-2025-38071: Undefined Security Weakness

In the Linux kernel, the following vulnerability has been resolved: x86/mm: Check return value from memblockphysallocrange At least with CONFIGPHYSICALSTART=0x100000, if there is 4 MiB of contiguous free memory available at this point, the kernel will crash and burn because memblockphysallocrange...