x86/mce/intel: Use MCG_BANKCNT_MASK instead of 0xff

Use the predefined MCG_BANKCNT_MASK macro instead of the hardcoded
0xff to mask the bank number bits.

No functional changes intended.

Signed-off-by: Qiuxu Zhuo <[email protected]>
Signed-off-by: Borislav Petkov (AMD) <[email protected]>
Reviewed-by: Tony Luck <[email protected]>
Reviewed-by: Nikolay Borisov <[email protected]>
Reviewed-by: Sohil Mehta <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

Author: qzhuo2

arch/x86/kernel/cpu/mce/intel.c

@@ -94,7 +94,7 @@ static int cmci_supported(int *banks)
 	if (!boot_cpu_has(X86_FEATURE_APIC) || lapic_get_maxlvt() < 6)
 		return 0;
 	rdmsrl(MSR_IA32_MCG_CAP, cap);
-	*banks = min_t(unsigned, MAX_NR_BANKS, cap & 0xff);
+	*banks = min_t(unsigned, MAX_NR_BANKS, cap & MCG_BANKCNT_MASK);
 	return !!(cap & MCG_CMCI_P);
 }