x86/entry: Correct reference to intended CONFIG_64_BIT

Commit in Fixes adds a condition with IS_ENABLED(CONFIG_64_BIT),
but the intended config item is called CONFIG_64BIT, as defined in
arch/x86/Kconfig.

Fortunately, scripts/checkkconfigsymbols.py warns:

64_BIT
Referencing files: arch/x86/include/asm/entry-common.h

Correct the reference to the intended config symbol.

Fixes: 662a022 ("x86/entry: Fix AC assertion")
Suggested-by: Randy Dunlap <[email protected]>
Signed-off-by: Lukas Bulwahn <[email protected]>
Signed-off-by: Borislav Petkov <[email protected]>
Cc: <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]

arch/x86/include/asm/entry-common.h

@@ -25,7 +25,7 @@ static __always_inline void arch_check_user_regs(struct pt_regs *regs)
 		 * For !SMAP hardware we patch out CLAC on entry.
 		 */
 		if (boot_cpu_has(X86_FEATURE_SMAP) ||
-		    (IS_ENABLED(CONFIG_64_BIT) && boot_cpu_has(X86_FEATURE_XENPV)))
+		    (IS_ENABLED(CONFIG_64BIT) && boot_cpu_has(X86_FEATURE_XENPV)))
 			mask |= X86_EFLAGS_AC;
 
 		WARN_ON_ONCE(flags & mask);