x86/entry/64: Add instruction suffix

Omitting suffixes from instructions in AT&T mode is bad practice when
operand size cannot be determined by the assembler from register
operands, and is likely going to be warned about by upstream gas in the
future (mine does already). Add the single missing suffix here.
Signed-off-by: NJan Beulich <jbeulich@suse.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/5A93F96902000078001ABAC8@prv-mh.provo.novell.com

arch/x86/entry/entry_64.S

@@ -55,7 +55,7 @@ END(native_usergs_sysret64)
 
 .macro TRACE_IRQS_FLAGS flags:req
 #ifdef CONFIG_TRACE_IRQFLAGS
-	bt	$9, \flags		/* interrupts off? */
+	btl	$9, \flags		/* interrupts off? */
 	jnc	1f
 	TRACE_IRQS_ON
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