tile: ftrace: Remove check of obsolete variable function_trace_stop

Nothing sets function_trace_stop to disable function tracing anymore.
Remove the check for it in the arch code.

Cc: Chris Metcalf <[e-mail]>
Acked-by: Zhigang Lu<[e-mail]>
Signed-off-by: Steven Rostedt <[e-mail]>

arch/tile/Kconfig

···
 	select SPARSE_IRQ
 	select GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
 	select HAVE_FUNCTION_TRACER
-	select HAVE_FUNCTION_TRACE_MCOUNT_TEST
 	select HAVE_FUNCTION_GRAPH_TRACER
 	select HAVE_DYNAMIC_FTRACE
 	select HAVE_FTRACE_MCOUNT_RECORD

arch/tile/kernel/mcount_64.S

···
 
 	.align	64
 STD_ENTRY(ftrace_caller)
-	moveli	r11, hw2_last(function_trace_stop)
-	{ shl16insli	r11, r11, hw1(function_trace_stop); move r12, lr }
-	{ shl16insli	r11, r11, hw0(function_trace_stop); move lr, r10 }
-	ld	r11, r11
-	beqz	r11, 1f
-	jrp	r12
-
-1:
-	{ move	r10, lr; move	lr, r12 }
 	MCOUNT_SAVE_REGS
 
 	/* arg1: self return address */
···
 
 	.align	64
 STD_ENTRY(__mcount)
-	moveli	r11, hw2_last(function_trace_stop)
-	{ shl16insli	r11, r11, hw1(function_trace_stop); move r12, lr }
-	{ shl16insli	r11, r11, hw0(function_trace_stop); move lr, r10 }
-	ld	r11, r11
-	beqz	r11, 1f
-	jrp	r12
-
-1:
-	{ move	r10, lr; move	lr, r12 }
 	{
 	 moveli	r11, hw2_last(ftrace_trace_function)
 	 moveli	r13, hw2_last(ftrace_stub)